A JS breakpoint set in the inspector will not be hit if the code is called from the debug console. To reproduce: 1. Open the above URL 2. Inspect the page 3. Go to the Scripts panel, and select the script "button%3E" from the drop-down 4. Put a breakpoint on line 1 5. Go back to the browser, and click the button in the page. Note that the breakpoint is hit. 6. Open the debug console, and run x() The function is called and returns 0, which prints to the console, but the breakpoint is not hit.
<rdar://problem/10269504>
I can not reproduce that on chromium ToT. Is it Safari specific or are you using an older version?
I cannot reproduce in Chrome either. Seems to be Safari-specific.