Fix some issues with charset handling during connect

* hostname and file paths are places where libmysqlclient ultimately only passes the string to an OS library so we should use whatever charset the OS expects, not mysql
* Even though _makeRawMySQLConnectionWithEncoding:isMasterConnection: takes an explicit charset argument most of the conversion logic simply used whatever charset the existing connection currently has, which is not neccesarily the one the new connection should use
* Add some remarks about the charset handling with passwords and mysql_error()
* Charsets do not apply to sqlstate.

3 files changed, 29 insertions, 8 deletions

diff --git a/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.h b/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.h
index 6f7b1a9a..77b70bf9 100644
--- a/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.h
+++ b/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.h
@@ -34,6 +34,7 @@
 @interface SPMySQLConnection (Conversion)
 
 + (const char *)_cStringForString:(NSString *)aString usingEncoding:(NSStringEncoding)anEncoding returningLengthAs:(NSUInteger *)cStringLengthPointer;
++ (NSString *)_stringForCString:(const char *)cString usingEncoding:(NSStringEncoding)encoding;
 
 - (const char *)_cStringForString:(NSString *)aString;
 - (NSString *)_stringForCString:(const char *)cString;
@@ -56,3 +57,16 @@ static inline const char* _cStringForStringWithEncoding(NSString* aString, NSStr
 
 	return (const char *)(*cachedMethodPointer)(cachedClass, cachedSelector, aString, anEncoding, cStringLengthPointer);
 }
+
+/**
+ * Converts a C string (NUL-terminated) to an NSString using the supplied encoding.
+ *
+ * Unlike +[NSString stringWithCString:encoding:] which will crash on a NULL pointer, this method will return nil instead.
+ */
+static inline NSString * _stringForCStringWithEncoding(const char *aString, NSStringEncoding inputEncoding)
+{
+	//This implementation is smaller than the cached selector voodoo above, so let's do it inline
+	
+	//NSString will crash on NULL ptr
+	return (aString == NULL)? nil : [NSString stringWithCString:aString encoding:inputEncoding];
+}
diff --git a/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.m b/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.m
index 676684ca..a7d293ea 100644
--- a/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.m
+++ b/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Conversion.m
@@ -79,7 +79,7 @@
 }
 
 /**
- * Converts a C string to an NSString using the supplied encoding.
+ * Converts a C string to an NSString using the current connection encoding.
  * This method *will not* correctly preserve nul characters within c strings; instead
  * the first nul character within the string will be treated as the line ending. This
  * is unavoidable without supplying a string length, so this method should not be widely
@@ -87,11 +87,15 @@
  */
 - (NSString *)_stringForCString:(const char *)cString
 {
+	return _stringForCStringWithEncoding(cString, stringEncoding);
+}
 
-	// Don't try and convert null strings
-	if (cString == NULL) return nil;
-
-	return [NSString stringWithCString:cString encoding:stringEncoding];
+/**
+ * @see _stringForCStringWithEncoding()
+ */
++ (NSString *)_stringForCString:(const char *)cString usingEncoding:(NSStringEncoding)encoding
+{
+	return _stringForCStringWithEncoding(cString, encoding);
 }
 
 @end
diff --git a/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Querying & Preparation.m b/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Querying & Preparation.m
index 594756be..ef98a21c 100644
--- a/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Querying & Preparation.m
+++ b/Frameworks/SPMySQLFramework/Source/SPMySQLConnection Categories/Querying & Preparation.m
@@ -323,7 +323,8 @@
 			// Store the error state
 			theErrorMessage = [self _stringForCString:mysql_error(mySQLConnection)];
 			theErrorID = mysql_errno(mySQLConnection);
-			theSqlstate = [self _stringForCString:mysql_sqlstate(mySQLConnection)];
+			// sqlstate is always an ASCII string, regardless of charset (but use latin1 anyway as that is less picky about invalid bytes)
+			theSqlstate = _stringForCStringWithEncoding(mysql_sqlstate(mySQLConnection), NSISOLatin1StringEncoding);
 
 			// Prevent retries if the query was cancelled or not a connection error
 			if (lastQueryWasCancelled || ![SPMySQLConnection isErrorIDConnectionError:theErrorID]) {
@@ -382,7 +383,8 @@
 			// Update the error message, if appropriate, to reflect result store errors or overall success
 			theErrorMessage = [self _stringForCString:mysql_error(mySQLConnection)];
 			theErrorID = mysql_errno(mySQLConnection);
-			theSqlstate = [self _stringForCString:mysql_sqlstate(mySQLConnection)];
+			// sqlstate is always an ASCII string, regardless of charset (but use latin1 anyway as that is less picky about invalid bytes)
+			theSqlstate = _stringForCStringWithEncoding(mysql_sqlstate(mySQLConnection), NSISOLatin1StringEncoding);
 		} else {
 			theResult = [[SPMySQLEmptyResult alloc] init];
 		}
@@ -735,7 +737,8 @@
 {
 	// If a SQLSTATE wasn't supplied, select one from the connection
 	if(!theSqlstate) {
-		theSqlstate = [self _stringForCString:mysql_sqlstate(mySQLConnection)];
+		// sqlstate is always an ASCII string, regardless of charset (but use latin1 anyway as that is less picky about invalid bytes)
+		theSqlstate = _stringForCStringWithEncoding(mysql_sqlstate(mySQLConnection), NSISOLatin1StringEncoding);
 	}
 
 	// Clear the last SQLSTATE stored on the instance