Fix "in-row" insertion mode and add the corresponding logic to clear the stack back to row context

HTMLKit/HTMLParser.m

@@ -1873,7 +1873,7 @@
 	switch (token.type) {
 		case HTMLTokenTypeStartTag:
 			if ([token.asTagToken.tagName isEqualToAny:@"th", @"td", nil]) {
-				[_stackOfOpenElements clearBackToTableContext];
+				[_stackOfOpenElements clearBackToTableRowContext];
 				[self insertElementForToken:token.asTagToken];
 				[self switchInsertionMode:HTMLInsertionModeInCell];
 				[_listOfActiveFormattingElements addMarker];

HTMLKit/HTMLStackOfOpenElements.h

@@ -32,6 +32,7 @@
 - (void)popElementsUntilElementPopped:(HTMLElement *)element;
 - (void)clearBackToTableContext;
 - (void)clearBackToTableBodyContext;
+- (void)clearBackToTableRowContext;
 - (void)popAll;
 
 - (HTMLElement *)hasElementInScopeWithTagName:(NSString *)tagName;

HTMLKit/HTMLStackOfOpenElements.m

@@ -152,6 +152,13 @@
 	}
 }
 
+- (void)clearBackToTableRowContext
+{
+	while (![self.currentNode.tagName isEqualToAny:@"tr", @"template", @"html", nil]) {
+		[_stack removeLastObject];
+	}
+}
+
 - (void)popAll
 {
 	[_stack removeAllObjects];