326874 - "ASSERTION: |First()| called on an empty string" opening Tools menu

Status: RESOLVED FIXED

(Core Graveyard :: Widget: Mac, defect)

Description

[Jesse Ruderman]

Steps to reproduce:
1. Open the Tools menu in Firefox.

Result: 
ASSERTION: |First()| called on an empty string: 'mLength > 0'

If I open the Tools menu again immediately, I don't see the assertion again, but if I reload the page, opening the Tools menu again does trigger the assertion again.

This is with a Mac debug build from a few days ago, with no extensions enabled.

Stack trace (with XPCOM_DEBUG_BREAK=abort) :

#0  0x9004716c in kill ()
#1  0x90128b98 in abort ()
#2  0x005f7f1c in PR_Abort () at /Users/admin/trunk/mozilla/nsprpub/pr/src/io/prlog.c:505
#3  0x01343c04 in Abort (aMsg=0xbfffd370 "\a###!!! ASSERTION: |First()| called on an empty string: 'mLength > 0', file ../../../dist/include/string/nsTSubstring.h, line 201") at /Users/admin/trunk/mozilla/xpcom/base/nsDebugImpl.cpp:358
#4  0x01343bc8 in NS_DebugBreak_P (aSeverity=1, aStr=0x8239e24 "|First()| called on an empty string", aExpr=0x8239e48 "mLength > 0", aFile=0x8238a38 "../../../dist/include/string/nsTSubstring.h", aLine=201) at /Users/admin/trunk/mozilla/xpcom/base/nsDebugImpl.cpp:341
#5  0x0825196c in nsCSubstring::First (this=0xbfffd990) at ../../../dist/include/string/nsTSubstring.h:201
#6  0x081e8708 in nsMenuX::AddMenuItem (this=0x22083620, aMenuItem=0x24e1f550) at /Users/admin/trunk/mozilla/widget/src/mac/nsMenuX.cpp:260
#7  0x081e84dc in nsMenuX::AddItem (this=0x22083620, aItem=0x24e1f550) at /Users/admin/trunk/mozilla/widget/src/mac/nsMenuX.cpp:230
#8  0x081eac88 in nsMenuX::LoadMenuItem (this=0x22083620, inParentMenu=0x22083620, inMenuItemContent=0x203f6120) at /Users/admin/trunk/mozilla/widget/src/mac/nsMenuX.cpp:899
#9  0x081e9848 in nsMenuX::MenuConstruct (this=0x22083620, aMenuEvent=@0xbfffe360, aParentWindow=0x0, aDocShell=0x1f966eb0) at /Users/admin/trunk/mozilla/widget/src/mac/nsMenuX.cpp:577
#10 0x081e9458 in nsMenuX::MenuSelected (this=0x22083620, aMenuEvent=@0xbfffe360) at /Users/admin/trunk/mozilla/widget/src/mac/nsMenuX.cpp:508
#11 0x081ea040 in MyMenuEventHandler (myHandler=0xbfffe530, event=0x24e163f0, userData=0x22083620) at /Users/admin/trunk/mozilla/widget/src/mac/nsMenuX.cpp:746
#12 0x9318cff4 in DispatchEventToHandlers ()
#13 0x9318c74c in SendEventToEventTargetInternal ()
#14 0x9318c5c8 in SendEventToEventTargetWithOptions ()
#15 0x93225c8c in SendMenuOpening ()
#16 0x9322580c in DrawTheMenu ()
#17 0x93225674 in MenuChanged ()
#18 0x932252dc in TrackMenuCommon ()
#19 0x932230bc in MenuSelectCore ()
#20 0x93222c7c in MenuSelect ()
#21 0x081de2ec in nsMacMessagePump::DoMouseDown (this=0x2937240, anEvent=@0xbfffeb60) at /Users/admin/trunk/mozilla/widget/src/mac/nsMacMessagePump.cpp:541
#22 0x081ddf28 in nsMacMessagePump::DispatchEvent (this=0x2937240, aRealEvent=1, anEvent=0xbfffeb60) at /Users/admin/trunk/mozilla/widget/src/mac/nsMacMessagePump.cpp:417
#23 0x081ddc64 in nsMacMessagePump::DoMessagePump (this=0x2937240) at /Users/admin/trunk/mozilla/widget/src/mac/nsMacMessagePump.cpp:289
#24 0x081cb038 in nsAppShell::Run (this=0x2931070) at /Users/admin/trunk/mozilla/widget/src/mac/nsAppShell.cpp:106
#25 0x08e0fa08 in nsAppStartup::Run (this=0x2931040) at /Users/admin/trunk/mozilla/toolkit/components/startup/src/nsAppStartup.cpp:161
#26 0x002109b4 in XRE_main (argc=1, argv=0xbffff0fc, aAppData=0x3078) at /Users/admin/trunk/mozilla/toolkit/xre/nsAppRunner.cpp:2331
#27 0x00002c8c in main (argc=1, argv=0xbffff0fc) at /Users/admin/trunk/mozilla/browser/app/nsBrowserApp.cpp:61

The code that (seemingly incorrectly) assumes that a string is not empty is Mac-specific, so I'm putting this bug in "Widget: Mac".  I don't know where the empty string is coming from, though -- is there an item in the tools menu that's doing something strangely?

Btw, I've seen this with the Go menu too.

Comment 1

[:Gavin Sharp [email: [e-mail]]]

I guess LoadMenuItem should not SetShortcutChar if the attribute is empty [1]? Or AddMenuItem could just filter it out [2]?.

Does this happen with the other menus that contain items without shortcut keys? Am I even looking at the right code? :)

Looks like the cocoa version doesn't do this, so I guess it'd be "fixed" by 326469.

[1] http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/widget/src/mac/nsMenuX.cpp&rev=1.61&mark=864-866#858
[2] http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/widget/src/mac/nsMenuX.cpp&rev=1.61&mark=260#241

Comment 2

[Josh Aas]

This would be fixed by moving to Cocoa widgets.

Comment 3

[Matthew (lilmatt) Willis]

*** Bug 332718 has been marked as a duplicate of this bug. ***

Comment 4

[Josh Aas]

Attachment: fix v1.0

Comment 5

[Josh Aas]

Comment on attachment 220175 [details] [diff] [review]
fix v1.0

This doesn't need to go on the 1.8 branch because it was recently caused by bryner in the patch for 323471.

Comment 6

[Josh Aas]

landed on trunk