Merge pull request #65 from Wevah/entity-fix

Re-encode special XML characters that aren't part of tags

Sources/ObjC/NSString+RSParser.h

@@ -14,6 +14,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSString *)rsparser_stringByDecodingHTMLEntities;
 
+/// Returns a copy of \c self with <, >, and & entity-encoded.
+@property (readonly, copy)	NSString	*rsparser_stringByEncodingRequiredEntities;
+
 - (NSString *)rsparser_md5Hash;
 
 - (BOOL)rsparser_contains:(NSString *)s;

Sources/ObjC/NSString+RSParser.m

@@ -112,6 +112,31 @@ - (NSString * _Nullable)rs_stringByDecodingEntity {
 	return nil;
 }
 
+- (NSString *)rsparser_stringByEncodingRequiredEntities {
+	NSMutableString *result = [NSMutableString string];
+
+	for (NSUInteger i = 0; i < self.length; ++i) {
+		unichar c = [self characterAtIndex:i];
+
+		switch (c) {
+			case '<':
+				[result appendString:@"&lt;"];
+				break;
+			case '>':
+				[result appendString:@"&gt;"];
+				break;
+			case '&':
+				[result appendString:@"&amp;"];
+				break;
+			default:
+				[result appendFormat:@"%C", c];
+				break;
+		}
+	}
+
+	return [result copy];
+}
+
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 - (NSData *)_rsparser_md5HashData {

Sources/ObjC/RSAtomParser.m

@@ -670,7 +670,9 @@ - (void)saxParser:(RSSAXParser *)SAXParser XMLCharactersFound:(const unsigned ch
 		if (s == nil) {
 			return;
 		}
-		[self.xhtmlString appendString:[[NSString alloc] initWithBytesNoCopy:(void *)characters length:length encoding:NSUTF8StringEncoding freeWhenDone:NO]];
+		// libxml decodes all entities; we need to re-encode certain characters
+		// (<, >, and &) when inside XHTML text content.
+		[self.xhtmlString appendString:s.rsparser_stringByEncodingRequiredEntities];
 	}
 }