Merge pull request #2072 from liuteng/master

fallback solution for NSString decode error

Author: dmoagx

Frameworks/SPMySQLFramework/Source/SPMySQLResult Categories/Data Conversion.m

@@ -247,9 +247,9 @@ static inline SPMySQLResultFieldProcessor _processorForField(MYSQL_FIELD aField)
 {
 
 	// Fast case - if not using a preview length, or if the data length is shorter, return the requested data.
-	if (previewLength == NSNotFound || dataLength <= previewLength) {
-		return [[[NSString alloc] initWithBytes:dataBytes length:dataLength encoding:aStringEncoding] autorelease];
-	}
+    if (previewLength == NSNotFound || dataLength <= previewLength) {
+        return [NSString stringForDataBytes:dataBytes length:dataLength encoding:aStringEncoding];
+    }
 
 	NSUInteger i = 0, characterLength = 0, byteLength = previewLength;
 	uint16_t continuationStart, continuationEnd;
@@ -394,7 +394,7 @@ static inline SPMySQLResultFieldProcessor _processorForField(MYSQL_FIELD aField)
 
 	// If returning the full string, use a fast path
 	if (byteLength >= dataLength) {
-		return [[[NSString alloc] initWithBytes:dataBytes length:dataLength encoding:aStringEncoding] autorelease];
+		return [NSString stringForDataBytes:dataBytes length:dataLength encoding:aStringEncoding];
 	}
 
 	// Get a string using the calculated details

Frameworks/SPMySQLFramework/Source/SPMySQLStringAdditions.h

@@ -33,5 +33,6 @@
 
 - (NSString *)mySQLBacktickQuotedString;
 - (NSString *)mySQLTickQuotedString;
++ (NSString *)stringForDataBytes:(const void *)dataBytes length:(NSUInteger)dataLength encoding:(NSStringEncoding)aStringEncoding;
 
 @end

Frameworks/SPMySQLFramework/Source/SPMySQLStringAdditions.m

@@ -52,4 +52,18 @@ - (NSString *)mySQLTickQuotedString
 	return [NSString stringWithFormat: @"'%@'", [self stringByReplacingOccurrencesOfString:@"'" withString:@"''"]];
 }
 
+/**
+ * Returns the string for the bytes according to the encoding, decode in ASCII if failed
+ */
++ (NSString *) stringForDataBytes:(const void *)dataBytes length:(NSUInteger)dataLength encoding:(NSStringEncoding)aStringEncoding
+{
+    NSString * string = [[[NSString alloc] initWithBytes:dataBytes length:dataLength encoding:aStringEncoding] autorelease];
+    
+    if (string == nil) {
+        return [[[NSString alloc] initWithBytes:dataBytes length:dataLength encoding:NSASCIIStringEncoding] autorelease];
+    }
+    
+    return string;
+}
+
 @end