From 2763eb75f25f28f2b407d1c2c89ac9cddf7f7392 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 13:12:45 +0200
Subject: [PATCH 01/36] IOS-2794 Use less bytes in truncateLeadingBytes

---
 pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
index 4993c8c..946a3fa 100644
--- a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
+++ b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
@@ -72,7 +72,9 @@ NS_ASSUME_NONNULL_BEGIN
         typeof(self) strongSelf = weakSelf;
         NSUInteger length = strongSelf.data.length - numBytes;
         NSData *newData =  [strongSelf.data subdataWithRange:NSMakeRange(numBytes, length)];
-        strongSelf.data = [NSMutableData dataWithData: newData];
+        [strongSelf.data replaceBytesInRange:NSMakeRange(0, length)
+                                   withBytes:newData.bytes];
+        strongSelf.data.length -= numBytes;
     });
 }
 

From 5d20e18bf87e16cfdbabb24546caa06446c80ee8 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 13:14:12 +0200
Subject: [PATCH 02/36] IOS-2794 Return own bytes, avoid copy

---
 pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
index 946a3fa..3af3744 100644
--- a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
+++ b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
@@ -84,8 +84,7 @@ NS_ASSUME_NONNULL_BEGIN
     __weak typeof(self) weakSelf = self;
     dispatch_sync(self.queue, ^{
         typeof(self) strongSelf = weakSelf;
-        NSData *copy = strongSelf.data.copy;
-        copyOfBytes = copy.bytes;
+        copyOfBytes = strongSelf.data.bytes;
     });
 
     return copyOfBytes;

From 514cc4b23c4239b0b3207612c063ee9f88d167c6 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 14:29:47 +0200
Subject: [PATCH 03/36] IOS-2794 Make that a mutable array

componentsSeparatedByCString
---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 2 +-
 pantomime-lib/Framework/Pantomime/CWPart.m                | 2 +-
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index b8db21e..1b369c7 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -255,7 +255,7 @@
   @result An instance of NSArray holding all components. The array is
           empty if the separator was not found in the receiver.
 */
-- (NSArray *) componentsSeparatedByCString: (const char *) theCString;
+- (NSMutableArray *) componentsSeparatedByCString: (const char *) theCString;
 
 /*!
   @method asciiString
diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index b2f670e..101330a 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -553,7 +553,7 @@ static int currentPartVersion = 2;
         dataToSend = [dataToSend wrapWithLimit: limit];
     }
 
-    NSArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
+    NSMutableArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
         if (i == count - 1 && [[allLines objectAtIndex: i] length] == 0) {
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index b7dbba7..2c3398b 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -734,7 +734,7 @@ static const char *hexDigit = "0123456789ABCDEF";
   return NSOrderedDescending;
 }
 
-- (NSArray *) componentsSeparatedByCString: (const char *) theCString
+- (NSMutableArray *) componentsSeparatedByCString: (const char *) theCString
 {
   NSMutableArray *aMutableArray;
   NSRange r1, r2;

From 224c0b961b901fa8b449572cbf5a785bf1f6d87f Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 15:04:04 +0200
Subject: [PATCH 04/36] IOS-2794 Check last line outside the loop

---
 pantomime-lib/Framework/Pantomime/CWPart.m | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index 101330a..e7124c7 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -554,11 +554,11 @@ static int currentPartVersion = 2;
     }
 
     NSMutableArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
+    if ([[allLines lastObject] length] == 0) {
+        [allLines removeLastObject];
+    }
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
-        if (i == count - 1 && [[allLines objectAtIndex: i] length] == 0) {
-            break;
-        }
         [dataValue appendData: [allLines objectAtIndex: i]];
         [dataValue appendBytes: LF  length: 1];
     }

From 18671718ca761c4139ba0674323311c588cb9ae7 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 15:07:44 +0200
Subject: [PATCH 05/36] IOS-2794 Lower memory consumption

---
 pantomime-lib/Framework/Pantomime/CWPart.m | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index e7124c7..4ece572 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -559,8 +559,9 @@ static int currentPartVersion = 2;
     }
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
-        [dataValue appendData: [allLines objectAtIndex: i]];
+        [dataValue appendData: [allLines objectAtIndex: 0]];
         [dataValue appendBytes: LF  length: 1];
+        [allLines removeObjectAtIndex:0];
     }
     return dataValue;
 }

From 16764a988f6b2b7f6ce915924615977afd9355e3 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 15:35:35 +0200
Subject: [PATCH 06/36] IOS-2794 Set to nil early

---
 pantomime-lib/Framework/Pantomime/CWSMTP.m | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pantomime-lib/Framework/Pantomime/CWSMTP.m b/pantomime-lib/Framework/Pantomime/CWSMTP.m
index e557dc6..1b0baad 100644
--- a/pantomime-lib/Framework/Pantomime/CWSMTP.m
+++ b/pantomime-lib/Framework/Pantomime/CWSMTP.m
@@ -679,6 +679,7 @@ static inline CWInternetAddress *next_recipient(NSMutableArray *theRecipients, B
       // We first replace all occurences of LF by CRLF in the Message's data.
       //
       aMutableData = [[NSMutableData dataWithData: _data] replaceLFWithCRLF];
+      _data = nil;
   
       //
       // According to RFC 2821 section 4.5.2, we must check for the character

From 88aa4005a1928b6d879974f26c91ac6f568e4e34 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Mon, 26 Apr 2021 15:50:29 +0200
Subject: [PATCH 07/36] IOS-2794 Tighten truncateLeadingBytes

---
 pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
index 3af3744..fa1a636 100644
--- a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
+++ b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
@@ -70,10 +70,9 @@ NS_ASSUME_NONNULL_BEGIN
     __weak typeof(self) weakSelf = self;
     dispatch_sync(self.queue, ^{
         typeof(self) strongSelf = weakSelf;
-        NSUInteger length = strongSelf.data.length - numBytes;
-        NSData *newData =  [strongSelf.data subdataWithRange:NSMakeRange(numBytes, length)];
-        [strongSelf.data replaceBytesInRange:NSMakeRange(0, length)
-                                   withBytes:newData.bytes];
+        NSUInteger theCount = strongSelf.data.length - numBytes;
+        char *theBytesTarget = [[strongSelf data] mutableBytes];
+        memmove(theBytesTarget, theBytesTarget + numBytes, theCount);
         strongSelf.data.length -= numBytes;
     });
 }

From a9a1cd7572bbb7230fe2ed6c0d4aa45853073211 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Tue, 27 Apr 2021 12:42:15 +0200
Subject: [PATCH 08/36] IOS-2794 Delete object after SMTP complete

---
 pantomime-lib/Framework/Pantomime/CWSMTP.m | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pantomime-lib/Framework/Pantomime/CWSMTP.m b/pantomime-lib/Framework/Pantomime/CWSMTP.m
index 1b0baad..82a8a46 100644
--- a/pantomime-lib/Framework/Pantomime/CWSMTP.m
+++ b/pantomime-lib/Framework/Pantomime/CWSMTP.m
@@ -725,6 +725,10 @@ static inline CWInternetAddress *next_recipient(NSMutableArray *theRecipients, B
       // The data we wrote in the previous call was sucessfully written.
       // We inform the delegate that the mail was sucessfully sent.
       PERFORM_SELECTOR_2(_delegate, @selector(messageSent:), PantomimeMessageSent, _message, @"Message");
+
+        // Delete memory consuming objects
+        _data = nil;
+        _message = nil;
     }
   else
     {

From 349806bd1774b43691e28fe7e183be5de233c635 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 10:27:58 +0200
Subject: [PATCH 09/36] IOS-2794 Less memory in
 _removeInvalidHeadersFromMessage

---
 pantomime-lib/Framework/Pantomime/CWIMAPFolder.m | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
index 2cceb2e..607e2ab 100644
--- a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
+++ b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
@@ -770,7 +770,7 @@
 - (NSData *) _removeInvalidHeadersFromMessage: (NSData *) theMessage
 {
   NSMutableData *aMutableData;
-  NSArray *allLines;
+  NSMutableArray *allLines;
   NSUInteger i, count;
 
   // We allocate our mutable data object
@@ -785,7 +785,10 @@
       NSData *aLine;
 
       // We get a line...
-      aLine = [allLines objectAtIndex: i];
+      aLine = [allLines firstObject];
+
+      // Remove the line immediately to easy memory consumption
+      [allLines removeObjectAtIndex:0];
 
       // We skip dumb headers
       if ([aLine hasCPrefix: "From "])

From 90f72c639fed6089e81fad2615921867ea6659fd Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 12:54:31 +0200
Subject: [PATCH 10/36] IOS-2794 Use firstObject uniformly

---
 pantomime-lib/Framework/Pantomime/CWPart.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index 4ece572..b0a6578 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -559,7 +559,7 @@ static int currentPartVersion = 2;
     }
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
-        [dataValue appendData: [allLines objectAtIndex: 0]];
+        [dataValue appendData: [allLines firstObject]];
         [dataValue appendBytes: LF  length: 1];
         [allLines removeObjectAtIndex:0];
     }

From e68cbbe15b535215aec301d7e96acc30c930f186 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:06:28 +0200
Subject: [PATCH 11/36] IOS-2794 Test subdata copying

---
 .../Pantomime/NSData+ExtensionsTest.m          | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m b/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m
index fa61490..eef7326 100644
--- a/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m
+++ b/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m
@@ -205,6 +205,24 @@ static NSString *text = @"My test\t Text containing 1234567890ß? stuff";
     [self assertDataByTrimmingWhiteSpacesFromTestStringUsedInFormat:testFormat];
 }
 
+#pragma mark - subdata
+
+/// This test proves that `[NSData subdataWithRange]` _copies_ the bytes it covers to a new buffer.
+- (void)testSubdataWithRange
+{
+    NSString *testStr = @"<35BE75EB.74E6.4CB7.9C5D.432B241FDF90@pretty.Easy.privacy>";
+    NSData *testData = [testStr dataUsingEncoding:NSASCIIStringEncoding];
+
+    NSRange r1 = NSMakeRange(0, 5);
+    NSData *subDataFromStart = [testData subdataWithRange:r1];
+    XCTAssertNotEqual([testData bytes], [subDataFromStart bytes]);
+
+    NSInteger offset = 5;
+    NSRange r2 = NSMakeRange(offset, 5);
+    NSData *subDataFromOffset = [testData subdataWithRange:r2];
+    XCTAssertNotEqual([testData bytes] + offset, [subDataFromOffset bytes]);
+}
+
 #pragma mark helper
 
 - (void)assertDataByTrimmingWhiteSpacesFromTestStringUsedInFormat:(NSString *)format

From 9fe5f23be38e2891d7a059b539650bafd877741b Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:16:29 +0200
Subject: [PATCH 12/36] IOS-2794 Revert "Use firstObject uniformly"

This reverts commit 90f72c639fed6089e81fad2615921867ea6659fd.
---
 pantomime-lib/Framework/Pantomime/CWPart.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index b0a6578..4ece572 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -559,7 +559,7 @@ static int currentPartVersion = 2;
     }
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
-        [dataValue appendData: [allLines firstObject]];
+        [dataValue appendData: [allLines objectAtIndex: 0]];
         [dataValue appendBytes: LF  length: 1];
         [allLines removeObjectAtIndex:0];
     }

From b222a98ea037619e861bfe89767cab582bc173dd Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:16:50 +0200
Subject: [PATCH 13/36] IOS-2794 Revert "Less memory in
 _removeInvalidHeadersFromMessage"

This reverts commit 349806bd1774b43691e28fe7e183be5de233c635.
---
 pantomime-lib/Framework/Pantomime/CWIMAPFolder.m | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
index 607e2ab..2cceb2e 100644
--- a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
+++ b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
@@ -770,7 +770,7 @@
 - (NSData *) _removeInvalidHeadersFromMessage: (NSData *) theMessage
 {
   NSMutableData *aMutableData;
-  NSMutableArray *allLines;
+  NSArray *allLines;
   NSUInteger i, count;
 
   // We allocate our mutable data object
@@ -785,10 +785,7 @@
       NSData *aLine;
 
       // We get a line...
-      aLine = [allLines firstObject];
-
-      // Remove the line immediately to easy memory consumption
-      [allLines removeObjectAtIndex:0];
+      aLine = [allLines objectAtIndex: i];
 
       // We skip dumb headers
       if ([aLine hasCPrefix: "From "])

From 574f415350b9086f642dcfb83b1019ed978fec6d Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:17:01 +0200
Subject: [PATCH 14/36] IOS-2794 Revert "Lower memory consumption"

This reverts commit 18671718ca761c4139ba0674323311c588cb9ae7.
---
 pantomime-lib/Framework/Pantomime/CWPart.m | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index 4ece572..e7124c7 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -559,9 +559,8 @@ static int currentPartVersion = 2;
     }
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
-        [dataValue appendData: [allLines objectAtIndex: 0]];
+        [dataValue appendData: [allLines objectAtIndex: i]];
         [dataValue appendBytes: LF  length: 1];
-        [allLines removeObjectAtIndex:0];
     }
     return dataValue;
 }

From 8113bd859b7a64cf47a057cacbb9c990b2080c2d Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:19:17 +0200
Subject: [PATCH 15/36] IOS-2794 Revert "Check last line outside the loop"

This reverts commit 224c0b961b901fa8b449572cbf5a785bf1f6d87f.
---
 pantomime-lib/Framework/Pantomime/CWPart.m | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index e7124c7..101330a 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -554,11 +554,11 @@ static int currentPartVersion = 2;
     }
 
     NSMutableArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
-    if ([[allLines lastObject] length] == 0) {
-        [allLines removeLastObject];
-    }
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
+        if (i == count - 1 && [[allLines objectAtIndex: i] length] == 0) {
+            break;
+        }
         [dataValue appendData: [allLines objectAtIndex: i]];
         [dataValue appendBytes: LF  length: 1];
     }

From 6f90df8cf7b7fb8d1ce6a4f7bb79c530e095017e Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:19:29 +0200
Subject: [PATCH 16/36] IOS-2794 Revert "Make that a mutable array"

This reverts commit 514cc4b23c4239b0b3207612c063ee9f88d167c6.
---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 2 +-
 pantomime-lib/Framework/Pantomime/CWPart.m                | 2 +-
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index 1b369c7..b8db21e 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -255,7 +255,7 @@
   @result An instance of NSArray holding all components. The array is
           empty if the separator was not found in the receiver.
 */
-- (NSMutableArray *) componentsSeparatedByCString: (const char *) theCString;
+- (NSArray *) componentsSeparatedByCString: (const char *) theCString;
 
 /*!
   @method asciiString
diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index 101330a..b2f670e 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -553,7 +553,7 @@ static int currentPartVersion = 2;
         dataToSend = [dataToSend wrapWithLimit: limit];
     }
 
-    NSMutableArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
+    NSArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
     NSUInteger count = [allLines count];
     for (int i = 0; i < count; i++) {
         if (i == count - 1 && [[allLines objectAtIndex: i] length] == 0) {
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 2c3398b..b7dbba7 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -734,7 +734,7 @@ static const char *hexDigit = "0123456789ABCDEF";
   return NSOrderedDescending;
 }
 
-- (NSMutableArray *) componentsSeparatedByCString: (const char *) theCString
+- (NSArray *) componentsSeparatedByCString: (const char *) theCString
 {
   NSMutableArray *aMutableArray;
   NSRange r1, r2;

From 39275525216c778f33011b6837a04d91edfa8454 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:27:49 +0200
Subject: [PATCH 17/36] IOS-2794 Wrong approach

---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 3 +++
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m     | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index b8db21e..853b3a9 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -158,6 +158,9 @@
 */
 - (NSData *) subdataToIndex: (NSUInteger) theIndex;
 
+/// Like `subDataWithRange`, but doesn't copy bytes, and instead points to the bytes from the original.
+- (NSData *)subdataUncopiedWithRange:(NSRange)range;
+
 /**
  @discussion Simple method to trim the leading and trailing whitespaces (characters with no visible
  representation). Cahracters currently taken into accout are:
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index b7dbba7..00faad7 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -437,6 +437,13 @@ static const char *hexDigit = "0123456789ABCDEF";
   return [self subdataWithRange: NSMakeRange(0, theIndex)];
 }
 
+- (NSData *)subdataUncopiedWithRange:(NSRange)range
+{
+    const char *theBytes = [self bytes];
+    const char *newBytes = theBytes + range.location;
+    return [NSData dataWithBytesNoCopy:(void *) newBytes length:range.length];
+}
+
 - (NSData *)dataByTrimmingWhiteSpaces
 {
     const char *bytes = [self bytes];

From dce3db0fee31f06a2c2ecea2f3ef4a6fe2f1c371 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:37:28 +0200
Subject: [PATCH 18/36] IOS-2794 This could work

---
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 00faad7..6f100cf 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -441,7 +441,14 @@ static const char *hexDigit = "0123456789ABCDEF";
 {
     const char *theBytes = [self bytes];
     const char *newBytes = theBytes + range.location;
-    return [NSData dataWithBytesNoCopy:(void *) newBytes length:range.length];
+
+    // Let the NSData point to existing bytes without copy,
+    // and don't do anything to free them
+    return [[NSData alloc] initWithBytesNoCopy:(void *) newBytes
+                                        length:range.length
+                                   deallocator:^(void * _Nonnull bytes, NSUInteger length) {
+        // ignore, don't free anything
+    }];
 }
 
 - (NSData *)dataByTrimmingWhiteSpaces

From 27c43d4a9b07c3f56d703dea8c8aa199ae7e9a4b Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 14:41:28 +0200
Subject: [PATCH 19/36] IOS-2794 Dare to use subdataUncopiedWithRange

componentsSeparatedByCString
---
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 6f100cf..7ebdd26 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -764,7 +764,7 @@ static const char *hexDigit = "0123456789ABCDEF";
   
   while (r2.length)
     {
-      [aMutableArray addObject: [self subdataWithRange: NSMakeRange(r1.location, r2.location - r1.location)]];
+      [aMutableArray addObject: [self subdataUncopiedWithRange: NSMakeRange(r1.location, r2.location - r1.location)]];
       r1.location = r2.location + r2.length;
       r1.length = len - r1.location;
       

From cc019e5deefde4713beffae8bcbbca7c6456f67a Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 15:08:55 +0200
Subject: [PATCH 20/36] IOS-2794 Revert "Dare to use subdataUncopiedWithRange"

This reverts commit 27c43d4a9b07c3f56d703dea8c8aa199ae7e9a4b.
---
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 7ebdd26..6f100cf 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -764,7 +764,7 @@ static const char *hexDigit = "0123456789ABCDEF";
   
   while (r2.length)
     {
-      [aMutableArray addObject: [self subdataUncopiedWithRange: NSMakeRange(r1.location, r2.location - r1.location)]];
+      [aMutableArray addObject: [self subdataWithRange: NSMakeRange(r1.location, r2.location - r1.location)]];
       r1.location = r2.location + r2.length;
       r1.length = len - r1.location;
       

From 977caf2398de8db6e4764efa5eb63d638f808ebc Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 15:30:09 +0200
Subject: [PATCH 21/36] IOS-2794 Optimized componentsSeparatedByCString

---
 .../PantomimeFramework/NSData+Extensions.h    |  4 ++++
 .../Framework/Pantomime/NSData+Extensions.m   | 23 +++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index 853b3a9..f1b363c 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -260,6 +260,10 @@
 */
 - (NSArray *) componentsSeparatedByCString: (const char *) theCString;
 
+/// Like `componentsSeparatedByCString`, but calls the given block with each result and the current count.
+- (void)componentsSeparatedByCString:(const char *)theCString
+                               block:(void (^)(NSData *, NSUInteger))block;
+
 /*!
   @method asciiString
   @discussion This method turns the receiver into a NSString object.
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 6f100cf..1570366 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -776,6 +776,29 @@ static const char *hexDigit = "0123456789ABCDEF";
   return AUTORELEASE(aMutableArray);
 }
 
+- (void)componentsSeparatedByCString:(const char *)theCString
+                               block:(void (^)(NSData *, NSUInteger))block
+{
+    NSUInteger len = [self length];
+    NSRange r1 = NSMakeRange(0,len);
+
+    NSRange r2 = [self rangeOfCString: theCString
+                              options: 0
+                                range: r1];
+
+
+    NSUInteger count = 0;
+    while (r2.length) {
+        block([self subdataWithRange: NSMakeRange(r1.location, r2.location - r1.location)], count);
+        count++;
+        r1.location = r2.location + r2.length;
+        r1.length = len - r1.location;
+
+        r2 = [self rangeOfCString: theCString  options: 0  range: r1];
+    }
+
+    block([self subdataWithRange: NSMakeRange(r1.location, len - r1.location)], count);
+}
 
 //
 //

From fee9757a1a9b748788386febf29f19a978c7ee13 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 16:53:12 +0200
Subject: [PATCH 22/36] IOS-2794 _removeInvalidHeadersFromMessage

---
 .../Framework/Pantomime/CWIMAPFolder.m        | 38 ++++++-------------
 1 file changed, 12 insertions(+), 26 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
index 2cceb2e..4e2cc9c 100644
--- a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
+++ b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
@@ -769,35 +769,21 @@
 //
 - (NSData *) _removeInvalidHeadersFromMessage: (NSData *) theMessage
 {
-  NSMutableData *aMutableData;
-  NSArray *allLines;
-  NSUInteger i, count;
-
-  // We allocate our mutable data object
-  aMutableData = [[NSMutableData alloc] initWithCapacity: [theMessage length]];
+    // We allocate our mutable data object
+    NSMutableData *aMutableData = [[NSMutableData alloc] initWithCapacity: [theMessage length]];
   
-  // We now replace all \n by \r\n
-  allLines = [theMessage componentsSeparatedByCString: "\n"];
-  count = [allLines count];
-
-  for (i = 0; i < count; i++)
-    {
-      NSData *aLine;
-
-      // We get a line...
-      aLine = [allLines objectAtIndex: i];
-
-      // We skip dumb headers
-      if ([aLine hasCPrefix: "From "])
-	{
-	  continue;
-	}
+    // We now replace all \n by \r\n
+    [theMessage componentsSeparatedByCString:"\n" block:^(NSData *aLine, NSUInteger count) {
+        // We skip dumb headers
+        if ([aLine hasCPrefix: "From "]) {
+            return;
+        }
 
-      [aMutableData appendData: aLine];
-      [aMutableData appendCString: "\r\n"];
-    }
+        [aMutableData appendData: aLine];
+        [aMutableData appendCString: "\r\n"];
+    }];
 
-  return AUTORELEASE(aMutableData);
+    return AUTORELEASE(aMutableData);
 }
 
 @end

From e981d0f7de1760534b761ef73735399eac66d7be Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:04:01 +0200
Subject: [PATCH 23/36] IOS-2794 Block parameter for if it's the last

componentsSeparatedByCString
---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 3 ++-
 pantomime-lib/Framework/Pantomime/CWIMAPFolder.m          | 4 +++-
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m     | 8 +++++---
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index f1b363c..faa05c3 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -261,8 +261,9 @@
 - (NSArray *) componentsSeparatedByCString: (const char *) theCString;
 
 /// Like `componentsSeparatedByCString`, but calls the given block with each result and the current count.
+/// The block will be invoked for every component, together with its count and a boolean denoting if it's the last element.
 - (void)componentsSeparatedByCString:(const char *)theCString
-                               block:(void (^)(NSData *, NSUInteger))block;
+                               block:(void (^)(NSData *, NSUInteger, BOOL isLast))block;
 
 /*!
   @method asciiString
diff --git a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
index 4e2cc9c..6c7ed28 100644
--- a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
+++ b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
@@ -773,7 +773,9 @@
     NSMutableData *aMutableData = [[NSMutableData alloc] initWithCapacity: [theMessage length]];
   
     // We now replace all \n by \r\n
-    [theMessage componentsSeparatedByCString:"\n" block:^(NSData *aLine, NSUInteger count) {
+    [theMessage componentsSeparatedByCString:"\n" block:^(NSData *aLine,
+                                                          NSUInteger count,
+                                                          BOOL isLast) {
         // We skip dumb headers
         if ([aLine hasCPrefix: "From "]) {
             return;
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 1570366..70748e6 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -777,7 +777,7 @@ static const char *hexDigit = "0123456789ABCDEF";
 }
 
 - (void)componentsSeparatedByCString:(const char *)theCString
-                               block:(void (^)(NSData *, NSUInteger))block
+                               block:(void (^)(NSData *, NSUInteger, BOOL isLast))block
 {
     NSUInteger len = [self length];
     NSRange r1 = NSMakeRange(0,len);
@@ -789,7 +789,9 @@ static const char *hexDigit = "0123456789ABCDEF";
 
     NSUInteger count = 0;
     while (r2.length) {
-        block([self subdataWithRange: NSMakeRange(r1.location, r2.location - r1.location)], count);
+        block([self subdataWithRange: NSMakeRange(r1.location, r2.location - r1.location)],
+              count,
+              NO);
         count++;
         r1.location = r2.location + r2.length;
         r1.length = len - r1.location;
@@ -797,7 +799,7 @@ static const char *hexDigit = "0123456789ABCDEF";
         r2 = [self rangeOfCString: theCString  options: 0  range: r1];
     }
 
-    block([self subdataWithRange: NSMakeRange(r1.location, len - r1.location)], count);
+    block([self subdataWithRange: NSMakeRange(r1.location, len - r1.location)], count, YES);
 }
 
 //

From 47610e12533cf89eeb0bc8c754074ed0f25e4203 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:04:30 +0200
Subject: [PATCH 24/36] IOS-2794 Formatting

---
 pantomime-lib/Framework/Pantomime/CWIMAPFolder.m | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
index 6c7ed28..2c46760 100644
--- a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
+++ b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
@@ -773,9 +773,10 @@
     NSMutableData *aMutableData = [[NSMutableData alloc] initWithCapacity: [theMessage length]];
   
     // We now replace all \n by \r\n
-    [theMessage componentsSeparatedByCString:"\n" block:^(NSData *aLine,
-                                                          NSUInteger count,
-                                                          BOOL isLast) {
+    [theMessage componentsSeparatedByCString:"\n"
+                                       block:^(NSData *aLine,
+                                               NSUInteger count,
+                                               BOOL isLast) {
         // We skip dumb headers
         if ([aLine hasCPrefix: "From "]) {
             return;

From ea3bf3ff758ca998cf18eef19ce8208477fbeccf Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:07:13 +0200
Subject: [PATCH 25/36] IOS-2794 [CWPart dataValue]

---
 pantomime-lib/Framework/Pantomime/CWPart.m | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index b2f670e..4840730 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -553,15 +553,15 @@ static int currentPartVersion = 2;
         dataToSend = [dataToSend wrapWithLimit: limit];
     }
 
-    NSArray *allLines = [dataToSend componentsSeparatedByCString: "\n"];
-    NSUInteger count = [allLines count];
-    for (int i = 0; i < count; i++) {
-        if (i == count - 1 && [[allLines objectAtIndex: i] length] == 0) {
-            break;
+    [dataToSend componentsSeparatedByCString:"\n"
+                                       block:^(NSData *aLine, NSUInteger count, BOOL isLast) {
+        if (isLast && [aLine length] == 0) {
+            return;
         }
-        [dataValue appendData: [allLines objectAtIndex: i]];
-        [dataValue appendBytes: LF  length: 1];
-    }
+        [dataValue appendData:aLine];
+        [dataValue appendBytes:LF length:1];
+    }];
+
     return dataValue;
 }
 

From c1ec8e723617bb6e54f8ca033ffea4f7c4f0df5f Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:08:37 +0200
Subject: [PATCH 26/36] IOS-2794 Parameter names

---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 2 +-
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index faa05c3..4d191d5 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -263,7 +263,7 @@
 /// Like `componentsSeparatedByCString`, but calls the given block with each result and the current count.
 /// The block will be invoked for every component, together with its count and a boolean denoting if it's the last element.
 - (void)componentsSeparatedByCString:(const char *)theCString
-                               block:(void (^)(NSData *, NSUInteger, BOOL isLast))block;
+                               block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block;
 
 /*!
   @method asciiString
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 70748e6..393c393 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -777,7 +777,7 @@ static const char *hexDigit = "0123456789ABCDEF";
 }
 
 - (void)componentsSeparatedByCString:(const char *)theCString
-                               block:(void (^)(NSData *, NSUInteger, BOOL isLast))block
+                               block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block
 {
     NSUInteger len = [self length];
     NSRange r1 = NSMakeRange(0,len);

From bcff358b08d8f2500aa3c5452f317480b1c43ca2 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:10:10 +0200
Subject: [PATCH 27/36] IOS-2794 Use subdataUncopiedWithRange

---
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 393c393..1640495 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -789,7 +789,7 @@ static const char *hexDigit = "0123456789ABCDEF";
 
     NSUInteger count = 0;
     while (r2.length) {
-        block([self subdataWithRange: NSMakeRange(r1.location, r2.location - r1.location)],
+        block([self subdataUncopiedWithRange:NSMakeRange(r1.location, r2.location - r1.location)],
               count,
               NO);
         count++;

From 263fd8dd3f219c4dc6cf56ae28697a5049ba1771 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:11:01 +0200
Subject: [PATCH 28/36] IOS-2794 Docs

---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index 4d191d5..732fd3d 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -262,6 +262,7 @@
 
 /// Like `componentsSeparatedByCString`, but calls the given block with each result and the current count.
 /// The block will be invoked for every component, together with its count and a boolean denoting if it's the last element.
+/// @Note: Uses `subdataUncopiedWithRange` to produce the `NSData` parts.
 - (void)componentsSeparatedByCString:(const char *)theCString
                                block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block;
 

From e3bc83d472497a70e8908881bb63b8d7969839a2 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Wed, 28 Apr 2021 17:16:44 +0200
Subject: [PATCH 29/36] IOS-2794 Docs

---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index 732fd3d..decb539 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -159,6 +159,8 @@
 - (NSData *) subdataToIndex: (NSUInteger) theIndex;
 
 /// Like `subDataWithRange`, but doesn't copy bytes, and instead points to the bytes from the original.
+/// @note The caller has to make sure that the returned `NSData` does not exist longer than the `NSData` that owns
+/// the actual bytes.
 - (NSData *)subdataUncopiedWithRange:(NSRange)range;
 
 /**
@@ -262,7 +264,7 @@
 
 /// Like `componentsSeparatedByCString`, but calls the given block with each result and the current count.
 /// The block will be invoked for every component, together with its count and a boolean denoting if it's the last element.
-/// @Note: Uses `subdataUncopiedWithRange` to produce the `NSData` parts.
+/// @note Uses `subdataUncopiedWithRange` to produce the `NSData` parts.
 - (void)componentsSeparatedByCString:(const char *)theCString
                                block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block;
 

From 3d003446399837c6101309742264d32f516489c4 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Thu, 29 Apr 2021 09:33:41 +0200
Subject: [PATCH 30/36] IOS-2794 Don't use subdataUncopiedWithRange

---
 .../PantomimeFramework/NSData+Extensions.h       |  5 -----
 .../Framework/Pantomime/NSData+Extensions.m      | 16 +---------------
 2 files changed, 1 insertion(+), 20 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index decb539..ad984e9 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -158,11 +158,6 @@
 */
 - (NSData *) subdataToIndex: (NSUInteger) theIndex;
 
-/// Like `subDataWithRange`, but doesn't copy bytes, and instead points to the bytes from the original.
-/// @note The caller has to make sure that the returned `NSData` does not exist longer than the `NSData` that owns
-/// the actual bytes.
-- (NSData *)subdataUncopiedWithRange:(NSRange)range;
-
 /**
  @discussion Simple method to trim the leading and trailing whitespaces (characters with no visible
  representation). Cahracters currently taken into accout are:
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 1640495..e35f2a5 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -437,20 +437,6 @@ static const char *hexDigit = "0123456789ABCDEF";
   return [self subdataWithRange: NSMakeRange(0, theIndex)];
 }
 
-- (NSData *)subdataUncopiedWithRange:(NSRange)range
-{
-    const char *theBytes = [self bytes];
-    const char *newBytes = theBytes + range.location;
-
-    // Let the NSData point to existing bytes without copy,
-    // and don't do anything to free them
-    return [[NSData alloc] initWithBytesNoCopy:(void *) newBytes
-                                        length:range.length
-                                   deallocator:^(void * _Nonnull bytes, NSUInteger length) {
-        // ignore, don't free anything
-    }];
-}
-
 - (NSData *)dataByTrimmingWhiteSpaces
 {
     const char *bytes = [self bytes];
@@ -789,7 +775,7 @@ static const char *hexDigit = "0123456789ABCDEF";
 
     NSUInteger count = 0;
     while (r2.length) {
-        block([self subdataUncopiedWithRange:NSMakeRange(r1.location, r2.location - r1.location)],
+        block([self subdataWithRange:NSMakeRange(r1.location, r2.location - r1.location)],
               count,
               NO);
         count++;

From 83a6c72d2c568c92f3582f98ad9e2786371bfe15 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Thu, 29 Apr 2021 09:50:38 +0200
Subject: [PATCH 31/36] IOS-2794 Revert "Test subdata copying"

This reverts commit e68cbbe15b535215aec301d7e96acc30c930f186.
---
 .../Pantomime/NSData+ExtensionsTest.m          | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m b/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m
index eef7326..fa61490 100644
--- a/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m
+++ b/PantomimeFramework/PantomimeFrameworkTests/Pantomime/NSData+ExtensionsTest.m
@@ -205,24 +205,6 @@ static NSString *text = @"My test\t Text containing 1234567890ß? stuff";
     [self assertDataByTrimmingWhiteSpacesFromTestStringUsedInFormat:testFormat];
 }
 
-#pragma mark - subdata
-
-/// This test proves that `[NSData subdataWithRange]` _copies_ the bytes it covers to a new buffer.
-- (void)testSubdataWithRange
-{
-    NSString *testStr = @"<35BE75EB.74E6.4CB7.9C5D.432B241FDF90@pretty.Easy.privacy>";
-    NSData *testData = [testStr dataUsingEncoding:NSASCIIStringEncoding];
-
-    NSRange r1 = NSMakeRange(0, 5);
-    NSData *subDataFromStart = [testData subdataWithRange:r1];
-    XCTAssertNotEqual([testData bytes], [subDataFromStart bytes]);
-
-    NSInteger offset = 5;
-    NSRange r2 = NSMakeRange(offset, 5);
-    NSData *subDataFromOffset = [testData subdataWithRange:r2];
-    XCTAssertNotEqual([testData bytes] + offset, [subDataFromOffset bytes]);
-}
-
 #pragma mark helper
 
 - (void)assertDataByTrimmingWhiteSpacesFromTestStringUsedInFormat:(NSString *)format

From eef0b3b9debf5af2e20f599e45170c3f46a459d9 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Thu, 29 Apr 2021 11:48:17 +0200
Subject: [PATCH 32/36] IOS-2794 Docs

---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index ad984e9..0ba06bf 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -257,9 +257,8 @@
 */
 - (NSArray *) componentsSeparatedByCString: (const char *) theCString;
 
-/// Like `componentsSeparatedByCString`, but calls the given block with each result and the current count.
-/// The block will be invoked for every component, together with its count and a boolean denoting if it's the last element.
-/// @note Uses `subdataUncopiedWithRange` to produce the `NSData` parts.
+/// Like `componentsSeparatedByCString`, but calls the given block with each component, the current count, .
+/// and a boolean denoting if it's the last element.
 - (void)componentsSeparatedByCString:(const char *)theCString
                                block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block;
 

From 98a3c5386fb5e93630f0ee9661b3fa3629b3fef4 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Thu, 29 Apr 2021 12:12:55 +0200
Subject: [PATCH 33/36] IOS-2794 Format

---
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index e35f2a5..1d02c0a 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -768,9 +768,9 @@ static const char *hexDigit = "0123456789ABCDEF";
     NSUInteger len = [self length];
     NSRange r1 = NSMakeRange(0,len);
 
-    NSRange r2 = [self rangeOfCString: theCString
-                              options: 0
-                                range: r1];
+    NSRange r2 = [self rangeOfCString:theCString
+                              options:0
+                                range:r1];
 
 
     NSUInteger count = 0;
@@ -785,7 +785,7 @@ static const char *hexDigit = "0123456789ABCDEF";
         r2 = [self rangeOfCString: theCString  options: 0  range: r1];
     }
 
-    block([self subdataWithRange: NSMakeRange(r1.location, len - r1.location)], count, YES);
+    block([self subdataWithRange:NSMakeRange(r1.location, len - r1.location)], count, YES);
 }
 
 //

From 49784361b238283f3af3663e4b69696ad0c49c2e Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Thu, 29 Apr 2021 12:14:46 +0200
Subject: [PATCH 34/36] IOS-2794 Comments

---
 pantomime-lib/Framework/Pantomime/CWSMTP.m | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWSMTP.m b/pantomime-lib/Framework/Pantomime/CWSMTP.m
index 82a8a46..451de0f 100644
--- a/pantomime-lib/Framework/Pantomime/CWSMTP.m
+++ b/pantomime-lib/Framework/Pantomime/CWSMTP.m
@@ -679,7 +679,7 @@ static inline CWInternetAddress *next_recipient(NSMutableArray *theRecipients, B
       // We first replace all occurences of LF by CRLF in the Message's data.
       //
       aMutableData = [[NSMutableData dataWithData: _data] replaceLFWithCRLF];
-      _data = nil;
+      _data = nil; // save memory by deleting as soon as possible
   
       //
       // According to RFC 2821 section 4.5.2, we must check for the character
@@ -726,7 +726,7 @@ static inline CWInternetAddress *next_recipient(NSMutableArray *theRecipients, B
       // We inform the delegate that the mail was sucessfully sent.
       PERFORM_SELECTOR_2(_delegate, @selector(messageSent:), PantomimeMessageSent, _message, @"Message");
 
-        // Delete memory consuming objects
+        // Delete memory consuming objects as soon as possible
         _data = nil;
         _message = nil;
     }

From 7b295604f2fb5c0c6e2a1629f7810afa8ae7bd15 Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Fri, 30 Apr 2021 11:00:58 +0200
Subject: [PATCH 35/36] IOS-2794 Rename

enumerateComponentsSeperatedByString
---
 PantomimeFramework/PantomimeFramework/NSData+Extensions.h | 4 ++--
 pantomime-lib/Framework/Pantomime/CWIMAPFolder.m          | 8 ++++----
 pantomime-lib/Framework/Pantomime/CWPart.m                | 4 ++--
 pantomime-lib/Framework/Pantomime/NSData+Extensions.m     | 4 ++--
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
index 0ba06bf..eacf455 100644
--- a/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
+++ b/PantomimeFramework/PantomimeFramework/NSData+Extensions.h
@@ -259,8 +259,8 @@
 
 /// Like `componentsSeparatedByCString`, but calls the given block with each component, the current count, .
 /// and a boolean denoting if it's the last element.
-- (void)componentsSeparatedByCString:(const char *)theCString
-                               block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block;
+- (void)enumerateComponentsSeperatedByString:(const char *)theCString
+                                       block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block;
 
 /*!
   @method asciiString
diff --git a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
index 2c46760..4172ba2 100644
--- a/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
+++ b/pantomime-lib/Framework/Pantomime/CWIMAPFolder.m
@@ -773,10 +773,10 @@
     NSMutableData *aMutableData = [[NSMutableData alloc] initWithCapacity: [theMessage length]];
   
     // We now replace all \n by \r\n
-    [theMessage componentsSeparatedByCString:"\n"
-                                       block:^(NSData *aLine,
-                                               NSUInteger count,
-                                               BOOL isLast) {
+    [theMessage enumerateComponentsSeperatedByString:"\n"
+                                               block:^(NSData *aLine,
+                                                       NSUInteger count,
+                                                       BOOL isLast) {
         // We skip dumb headers
         if ([aLine hasCPrefix: "From "]) {
             return;
diff --git a/pantomime-lib/Framework/Pantomime/CWPart.m b/pantomime-lib/Framework/Pantomime/CWPart.m
index 4840730..9c0bf02 100644
--- a/pantomime-lib/Framework/Pantomime/CWPart.m
+++ b/pantomime-lib/Framework/Pantomime/CWPart.m
@@ -553,8 +553,8 @@ static int currentPartVersion = 2;
         dataToSend = [dataToSend wrapWithLimit: limit];
     }
 
-    [dataToSend componentsSeparatedByCString:"\n"
-                                       block:^(NSData *aLine, NSUInteger count, BOOL isLast) {
+    [dataToSend enumerateComponentsSeperatedByString:"\n"
+                                               block:^(NSData *aLine, NSUInteger count, BOOL isLast) {
         if (isLast && [aLine length] == 0) {
             return;
         }
diff --git a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
index 1d02c0a..dae8ae5 100644
--- a/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
+++ b/pantomime-lib/Framework/Pantomime/NSData+Extensions.m
@@ -762,8 +762,8 @@ static const char *hexDigit = "0123456789ABCDEF";
   return AUTORELEASE(aMutableArray);
 }
 
-- (void)componentsSeparatedByCString:(const char *)theCString
-                               block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block
+- (void)enumerateComponentsSeperatedByString:(const char *)theCString
+                                       block:(void (^)(NSData *aLine, NSUInteger count, BOOL isLast))block
 {
     NSUInteger len = [self length];
     NSRange r1 = NSMakeRange(0,len);

From 3a5ba594b838a4efd2e09e9f1161e5f3723f8dee Mon Sep 17 00:00:00 2001
From: Dirk Zimmermann <dz@pep.security>
Date: Fri, 30 Apr 2021 11:05:11 +0200
Subject: [PATCH 36/36] IOS-2794 Rename copyOfBytes -> bytes

---
 pantomime-lib/Framework/Pantomime/CWService+Protected.m   | 2 +-
 .../Framework/Pantomime/Utils/CWThreadSafeData.h          | 4 ++--
 .../Framework/Pantomime/Utils/CWThreadSafeData.m          | 8 ++++----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/pantomime-lib/Framework/Pantomime/CWService+Protected.m b/pantomime-lib/Framework/Pantomime/CWService+Protected.m
index 99a81dc..61d4321 100644
--- a/pantomime-lib/Framework/Pantomime/CWService+Protected.m
+++ b/pantomime-lib/Framework/Pantomime/CWService+Protected.m
@@ -60,7 +60,7 @@
         unsigned char *bytes;
         NSInteger count, len;
 
-        bytes = (unsigned char*)[_wbuf copyOfBytes];
+        bytes = (unsigned char*)[_wbuf bytes];
         len = [_wbuf length];
 
 #ifdef MACOSX
diff --git a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.h b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.h
index 7d8d6ca..69dbfa3 100644
--- a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.h
+++ b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.h
@@ -49,9 +49,9 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)truncateLeadingBytes:(NSUInteger)numBytes;
 
 /**
- @return a copy of the inner byte array.
+ @return a pointer to the inner byte array.
  */
-- (const char*)copyOfBytes;
+- (const char *)bytes;
 
 /**
  @discussion This method is used to obtain the subdata to <i>index</i>
diff --git a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
index fa1a636..5f58f06 100644
--- a/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
+++ b/pantomime-lib/Framework/Pantomime/Utils/CWThreadSafeData.m
@@ -77,16 +77,16 @@ NS_ASSUME_NONNULL_BEGIN
     });
 }
 
-- (const char*)copyOfBytes
+- (const char *)bytes
 {
-    __block const char* copyOfBytes = nil;
+    __block const char *theBytes = nil;
     __weak typeof(self) weakSelf = self;
     dispatch_sync(self.queue, ^{
         typeof(self) strongSelf = weakSelf;
-        copyOfBytes = strongSelf.data.bytes;
+        theBytes = strongSelf.data.bytes;
     });
 
-    return copyOfBytes;
+    return theBytes;
 }
 
 - (NSData *)subdataToIndex:(NSUInteger)index