Fix for bug 42196. A simple patch from Rod Spears to prevent asserts that were firing on reading mail messages.

content/html/document/src/nsHTMLFragmentContentSink.cpp

@@ -776,16 +776,18 @@ nsHTMLFragmentContentSink::GetAttributeValueAt(const nsIParserNode& aNode,
   aResult.Append(value);
 
   // Strip quotes if present
-  PRUnichar first = aResult.First();
-  if ((first == '\"') || (first == '\'')) {
-    if (aResult.Last() == first) {
-      aResult.Cut(0, 1);
-      PRInt32 pos = aResult.Length() - 1;
-      if (pos >= 0) {
-        aResult.Cut(pos, 1);
+  if (aResult.Length() > 0) {
+    PRUnichar first = aResult.First();
+    if ((first == '\"') || (first == '\'')) {
+      if (aResult.Last() == first) {
+        aResult.Cut(0, 1);
+        PRInt32 pos = aResult.Length() - 1;
+        if (pos >= 0) {
+          aResult.Cut(pos, 1);
+        }
+      } else {
+        // Mismatched quotes - leave them in
       }
-    } else {
-      // Mismatched quotes - leave them in
     }
   }
 

layout/html/document/src/nsHTMLFragmentContentSink.cpp

@@ -776,16 +776,18 @@ nsHTMLFragmentContentSink::GetAttributeValueAt(const nsIParserNode& aNode,
   aResult.Append(value);
 
   // Strip quotes if present
-  PRUnichar first = aResult.First();
-  if ((first == '\"') || (first == '\'')) {
-    if (aResult.Last() == first) {
-      aResult.Cut(0, 1);
-      PRInt32 pos = aResult.Length() - 1;
-      if (pos >= 0) {
-        aResult.Cut(pos, 1);
+  if (aResult.Length() > 0) {
+    PRUnichar first = aResult.First();
+    if ((first == '\"') || (first == '\'')) {
+      if (aResult.Last() == first) {
+        aResult.Cut(0, 1);
+        PRInt32 pos = aResult.Length() - 1;
+        if (pos >= 0) {
+          aResult.Cut(pos, 1);
+        }
+      } else {
+        // Mismatched quotes - leave them in
       }
-    } else {
-      // Mismatched quotes - leave them in
     }
   }