Reviewers: ihab.awad,
Description:
1. you can't use debugmode twice on the same page.
http://code.google.com/p/google-caja/issues/detail?id=637
cajole this in the testbed with debug on:
<script>function f(){}</script>
then try to cajole it again.
the second time fails "___ reused with different debug symbols"
this change fixes that by blithely allowing you to reuse ___ with
different debug symbols. this is not necessarily the right fix,
because two modules coexisting on the same page will stomp on each
other's debugging symbols, but this simple fix reduces frustration
with the testbed in the common case.
2. event handlers can screw up the debug stack and raise a
spurious exception.
http://code.google.com/p/google-caja/issues/detail?id=828
the current code assumes that event handlers are always
top-level entry points, and it clears the debug stack at
every event, but sometimes an event handler can fire
while we're in middle of executing some other js,
and on return from the eventhandler, debugmode tries to
pop from the empty stack, causing an exception.
this change fixes that in two ways:
a. event handlers will not clear the debug stack.
b. debugstack underflow will not raise an exception.
Please review this at http://codereview.appspot.com/88132
Affected files:
M src/com/google/caja/cajita-debugmode.js
Index: src/com/google/caja/cajita-debugmode.js
===================================================================
--- src/com/google/caja/cajita-debugmode.js (revision 3563)
+++ src/com/google/caja/cajita-debugmode.js (working copy)
@@ -39,10 +39,8 @@
* handler or a cross-frame event, can corrupt the stack. We try to detect
* these on popping a stack frame, and mark the stack invalid.
* <p>
- * The {...@code ___.startCallerStack} can be invoked by container
event/timeout
- * handling to initialize a stack. This will throw out an invalid stack,
and
- * start a new stack. If the stack is not empty and not marked invalid,
it will
- * be marked invalid.
+ * {...@code ___.startCallerStack} can be invoked by event handlers to set the
+ * stack to a valid state. If the stack is already valid, it's left alone.
*
* @author [email protected]
*/
@@ -62,6 +60,7 @@
for (var i = 0, n = members.length; i < n; i += 2) {
var k = members[i], v = members[i + 1];
if (!(k in obj)) { throw new Error('can\'t override ' + k + ' in ' +
v); }
+ if (obj[k] === v) continue;
if (extraOptionalParams !== null
&& obj[k].length + extraOptionalParams !== v.length) {
throw new Error('overriding ' + k + ' with a different signature');
@@ -72,19 +71,17 @@
// Define the stack, and accessors
var stack;
- var stackInvalid;
+ var stackInvalid = true;
/**
- * Resets the caller stack to an empty state.
- * Called by event handler wrapper to bring the stack into a known good
state
- * and similarly by {...@code setTimeout}/{...@code setInterval} wrappers
- * to associate the call stack at the time the timeout or interval was
- * registered for execution.
- * @param opt_precedingCallStack a sealed call stack.
+ * Start the caller stack if it hasn't been started already. Called by
+ * event handler, {...@code setTimeout}, and {...@code setInterval} wrappers
*/
- function startCallerStack(opt_precedingCallStack) {
- stack = [];
- stackInvalid = false;
+ function startCallerStack() {
+ if (!stack || stackInvalid) {
+ stack = [];
+ stackInvalid = false;
+ }
}
var stackSealer = cajita.makeSealerUnsealerPair();
@@ -108,10 +105,10 @@
}
function popFrame(stackFrame) {
- // Check that pushed item is at the top, and if so pop, invalidate
- // otherwise.
+ // If we're not popping what we expect, something weird has screwed up
+ // our push/pop symmetry, so we mark the stack invalid.
var top = stack.length - 1;
- if (stackFrame === stack[top]) {
+ if (top >= 0 && stackFrame === stack[top]) {
stack.length = top;
} else {
stackInvalid = true;
@@ -315,9 +312,6 @@
var newDebugSymbols = arguments;
cajita.log('using debug symbols');
if (!cajita.isJSONContainer(this)) { cajita.fail('called on bad ___');
}
- if (this.debugSymbols_ !== void 0) {
- cajita.fail('___ reused with different debug symbols');
- }
// Unpack the debugging symbols.
// Per DebuggingSymbolsStage:
@@ -379,4 +373,4 @@
startCallerStack();
})();
-
\ No newline at end of file
+
