Fixed crash. Added some comments.

src/data-types/mailstream.c

@@ -282,8 +282,9 @@ mailstream_low * mailstream_get_low(mailstream * s)
 static void low_logger(mailstream_low * s, int log_type,
   const char * str, size_t size, void * context)
 {
-  if (s->logger != NULL) {
-    s->logger(context, log_type, str, size, s->logger_context);
+  mailstream * stream = context;
+  if (stream->logger != NULL) {
+    stream->logger(context, log_type, str, size, stream->logger_context);
   }
 }
 

src/data-types/mailstream_low.c

@@ -71,10 +71,9 @@ void (* mailstream_logger_id)(mailstream_low * s, int is_stream_data, int direct
 static inline void mailstream_logger_internal(mailstream_low * s, int is_stream_data, int direction,
     const char * buffer, size_t size);
 
+// Will log a buffer.
 #define STREAM_LOG_ERROR(low, direction, buf, size) \
-  if (low->logger != NULL) { \
-    mailstream_logger_internal(low, 2, direction, buf, size); \
-  } \
+  mailstream_logger_internal(low, 2, direction, buf, size); \
   if (mailstream_debug) { \
 	  if (mailstream_logger_id != NULL) { \
 	    mailstream_logger_id(low, 2, direction, buf, size); \
@@ -99,10 +98,9 @@ static inline void mailstream_logger_internal(mailstream_low * s, int is_stream_
     } \
   }
 
+// Will log a buffer.
 #define STREAM_LOG_BUF(low, direction, buf, size) \
-  if (low->logger != NULL) { \
-    mailstream_logger_internal(low, 1, direction, buf, size); \
-  } \
+  mailstream_logger_internal(low, 1, direction, buf, size); \
   if (mailstream_debug) { \
   	if (mailstream_logger_id != NULL) { \
   	  mailstream_logger_id(low, 1, direction, buf, size); \
@@ -127,10 +125,9 @@ static inline void mailstream_logger_internal(mailstream_low * s, int is_stream_
     } \
   }
 
+// Will log some log text string.
 #define STREAM_LOG(low, direction, str) \
-  if (low->logger != NULL) { \
-    mailstream_logger_internal(low, 0, direction, buf, strlen(str)); \
-  } \
+  mailstream_logger_internal(low, 0, direction, buf, strlen(str)); \
   if (mailstream_debug) { \
   	if (mailstream_logger_id != NULL) { \
   	  mailstream_logger_id(low, 0, direction, str, strlen(str)); \
@@ -332,6 +329,9 @@ static inline void mailstream_logger_internal(mailstream_low * s, int is_stream_
 {
   int log_type = -1;
   
+  if (s->logger == NULL)
+    return;
+  
   /*
    stream data:
   0: log

src/data-types/mailstream_types.h

@@ -55,14 +55,17 @@ struct _mailstream_low;
 typedef struct _mailstream_low mailstream_low;
 
 enum {
+  // Buffer is a log text string.
   MAILSTREAM_LOG_TYPE_INFO_GENERIC,
   MAILSTREAM_LOG_TYPE_INFO_RECEIVED,
   MAILSTREAM_LOG_TYPE_INFO_SENT,
   
+  // Buffer is data sent over the network.
   MAILSTREAM_LOG_TYPE_ERROR_GENERIC,
   MAILSTREAM_LOG_TYPE_ERROR_RECEIVED,
   MAILSTREAM_LOG_TYPE_ERROR_SENT,
   
+  // Buffer is data sent over the network.
   MAILSTREAM_LOG_TYPE_DATA_RECEIVED,
   MAILSTREAM_LOG_TYPE_DATA_SENT,
   MAILSTREAM_LOG_TYPE_DATA_SENT_PRIVATE,