- Make a number of changes to attempt to improve disconnection/quit crashes: prevent multiple disconnects, add more checks, cancel current queries, and add a tiny delay to allow mysql cleanup.

 - Alter MCPStreamingResult to no longer return a retained instance, setting up correct result disposal on autorelease but changing callers to retain as soon as they receive.
 - Review and change a number of local variables shadowing/shielding other local or global variables.

4 files changed, 22 insertions, 8 deletions

diff --git a/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.h b/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.h
index f04fb26e..8e5a60f9 100644
--- a/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.h
+++ b/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.h
@@ -82,6 +82,7 @@ static inline NSData* NSStringDataUsingLossyEncoding(NSString* self, NSInteger e
 	NSLock			 *queryLock;	   /* Anything that performs a mysql_net_read is not thread-safe: mysql queries, pings */
 
 	BOOL useKeepAlive;
+	BOOL isDisconnecting;
 	NSInteger connectionTimeout;
 	CGFloat keepAliveInterval;
 	
diff --git a/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.m b/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.m
index f04fe226..607e1b8e 100644
--- a/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.m
+++ b/Frameworks/MCPKit/MCPFoundationKit/MCPConnection.m
@@ -106,6 +106,7 @@ static BOOL	sTruncateLongFieldInLogs = YES;
 		queryCancelUsedReconnect = NO;
 		serverVersionString = nil;
 		mTimeZone = nil;
+		isDisconnecting = NO;
 		
 		// Initialize ivar defaults
 		connectionTimeout = 10;
@@ -298,7 +299,7 @@ static BOOL	sTruncateLongFieldInLogs = YES;
 	if (mConnected && newState == PROXY_STATE_IDLE && currentProxyState == PROXY_STATE_CONNECTED) {
 		currentProxyState = newState;
 		[connectionProxy setConnectionStateChangeSelector:nil delegate:nil];
-		[self reconnect];
+		if (!isDisconnecting) [self reconnect];
 		
 		return;
 	}
@@ -404,14 +405,22 @@ static BOOL	sTruncateLongFieldInLogs = YES;
  */
 - (void)disconnect
 {
+	if (isDisconnecting) return;
+	isDisconnecting = YES;
+
 	[self stopKeepAliveTimer];
 
 	if (mConnected) {
+		[self cancelCurrentQuery];
+		mConnected = NO;
+		
+		// Small pause for cleanup.
+		usleep(100000);
 		mysql_close(mConnection);
 		mConnection = NULL;
 	}
 	
-	mConnected = NO;
+	isDisconnecting = NO;
 
 	if (connectionProxy) {
 		[connectionProxy performSelectorOnMainThread:@selector(disconnect) withObject:nil waitUntilDone:YES];
@@ -457,6 +466,7 @@ static BOOL	sTruncateLongFieldInLogs = YES;
 	}
 	
 	mConnected = NO;
+	isDisconnecting = NO;
 	
 	// If there is a tunnel, ensure it's disconnected and attempt to reconnect it in blocking fashion
 	if (connectionProxy) {
@@ -1290,7 +1300,6 @@ void performThreadedKeepAlive(void *ptr)
 
 /**
  * Takes a query string and returns an MCPStreamingResult representing the result of the query.
- * The returned MCPStreamingResult is retained and the client is responsible for releasing it.
  * If no fields are present in the result, nil will be returned.
  * Uses safe/fast mode, which may use more memory as results are downloaded.
  */
@@ -1301,7 +1310,6 @@ void performThreadedKeepAlive(void *ptr)
 
 /**
  * Takes a query string and returns an MCPStreamingResult representing the result of the query.
- * The returned MCPStreamingResult is retained and the client is responsible for releasing it.
  * If no fields are present in the result, nil will be returned.
  * Can be used in either fast/safe mode, where data is downloaded as fast as possible to avoid
  * blocking the server, or in full streaming mode for lowest memory usage but potentially blocking
@@ -1316,7 +1324,6 @@ void performThreadedKeepAlive(void *ptr)
  * Error checks connection extensively - if this method fails due to a connection error, it will ask how to
  * proceed and loop depending on the status, not returning control until either the query has been executed
  * and the result can be returned or the connection and document have been closed.
- * If using streamingResult, the caller is responsible for releasing the result set.
  */
 - (id)queryString:(NSString *) query usingEncoding:(NSStringEncoding) encoding streamingResult:(NSInteger) streamResultType
 {
@@ -1516,7 +1523,6 @@ void performThreadedKeepAlive(void *ptr)
 	(void)(*startKeepAliveTimerPtr)(self, startKeepAliveTimerSEL, YES);
 	
 	if (!theResult) return nil;
-	if (streamResultType != MCP_NO_STREAMING) return theResult;
 	return [theResult autorelease];
 }
 
@@ -1618,7 +1624,7 @@ void performThreadedKeepAlive(void *ptr)
 
 	// Reset the connection
 	[self unlockConnection];
-	[self reconnect];
+	if (!isDisconnecting) [self reconnect];
 
 	// Set queryCancelled again to handle requery cleanups, and return.
 	queryCancelled = YES;
diff --git a/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.h b/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.h
index 2f5ec638..65ee6423 100644
--- a/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.h
+++ b/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.h
@@ -53,6 +53,8 @@ typedef struct SP_MYSQL_ROWS {
 	unsigned long freedRowCount;
 	pthread_mutex_t dataCreationLock;
 	pthread_mutex_t dataFreeLock;
+	IMP isConnectedPtr;
+	SEL isConnectedSEL;
 }
 
 - (id)initWithMySQLPtr:(MYSQL *)mySQLPtr encoding:(NSStringEncoding)theEncoding timeZone:(NSTimeZone *)theTimeZone connection:(MCPConnection *)theConnection;
diff --git a/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.m b/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.m
index 624f132c..fd7d181b 100644
--- a/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.m
+++ b/Frameworks/MCPKit/MCPFoundationKit/MCPStreamingResult.m
@@ -95,6 +95,10 @@
 			mNumOfFields = 0;
 		}
 
+		// Obtain SEL references and pointer
+		isConnectedSEL = @selector(isConnected);
+		isConnectedPtr = [parentConnection methodForSelector:isConnectedSEL];
+
 		// If the result is opened in download-data-fast safe mode, set up the additional variables
 		// and threads required.
 		if (!fullyStreaming) {
@@ -127,6 +131,7 @@
  */
 - (void) dealloc
 {
+	[self cancelResultLoad];
 	if (!connectionUnlocked) [parentConnection unlockConnection];
 
 	if (!fullyStreaming) {
@@ -406,7 +411,7 @@
 	size_t sizeOfDataLengths = (size_t)(sizeof(unsigned long) * mNumOfFields);
 
 	// Loop through the rows until the end of the data is reached - indicated via a NULL
-	while (theRow = mysql_fetch_row(mResult)) {
+	while (	(BOOL)(*isConnectedPtr)(parentConnection, isConnectedSEL) && (theRow = mysql_fetch_row(mResult))) {
 
 		// Retrieve the lengths of the returned data
 		fieldLengths = mysql_fetch_lengths(mResult);