Refactor propagation of parsing errors for SVG attributes

third_party/WebKit/Source/core/svg/SVGAngleTearOff.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 96 matching lines @@
 
 void SVGAngleTearOff::setValueAsString(const String& value, ExceptionState& exceptionState)
 {
     if (isImmutable()) {
         exceptionState.throwDOMException(NoModificationAllowedError, "The attribute is read-only.");
         return;
     }
 
     String oldValue = target()->valueAsString();
 
-    target()->setValueAsString(value, exceptionState);
+    SVGParsingError status = target()->setValueAsString(value);
 
-    if (!exceptionState.hadException() && !hasExposedAngleUnit()) {
-        target()->setValueAsString(oldValue, ASSERT_NO_EXCEPTION); // rollback to old value

[pdr., 2015/12/23 04:00:08]

Is this rollback behavior spec'd? Not a big deal either way, just curious
because I don't see it in 1.1.

[fs, 2015/12/23 10:04:17]

As I recall this was subject of discussion in the WG [1] and only applies to the
cases where "new" units are used (as is the case here). I'll see if I can dig up
something.

[1] citation needed...

[fs, 2015/12/23 12:54:47]

After some mild digging I found:

http://www.w3.org/2014/06/12-svg-minutes.html#item01
https://svgwg.org/svg2-draft/types.html#InterfaceSVGLength (or SVGAngle; the
note after the list of unit enums)

The former refers to a previous resolution which I haven't dug up. As for the
spec bits I don't see that this behavior ended up as specified. (I only see it
being handled for unitType.)

+    if (status == NoError && !hasExposedAngleUnit()) {
+        target()->setValueAsString(oldValue); // rollback to old value
+        status = ParsingAttributeFailedError;
+    }
+    if (status != NoError) {
         exceptionState.throwDOMException(SyntaxError, "The value provided ('" + value + "') is invalid.");
         return;
     }
 
     commitChange();
 }
 
 }