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Bug 364073

Summary: [Compatibility] "Compare With" always done on same file regardless of selection
Product: [Eclipse Project] Platform Reporter: DJ Houghton <dj.houghton>
Component: UIAssignee: Remy Suen <remy.suen>
Status: VERIFIED FIXED QA Contact: Paul Webster <pwebster>
Severity: normal    
Priority: P3 CC: emoffatt, pwebster, remy.suen
Version: 4.2   
Target Milestone: 4.2 M4   
Hardware: All   
OS: All   
Whiteboard:

Description DJ Houghton CLA 2011-11-17 13:36:12 EST 
Eclipse EGit	1.2.0.201111160714
Eclipse SDK	4.2.0.I20111116-0810

Perhaps related to Bug 358020.

I had a case yesterday where I was selecting a (git) file in the Package Explorer and doing a Compare With -> Branch, Tag or Reference. I would choose a tag to compare with but when the compare view opened, the compare was being done on a different file altogether. 

I tried it multiple times but it consistently compared against the same wrong file.

I talked to John and he pointed out the path was incorrect in the top of the compare dialog and mentioned there was a perhaps related problem recently fixed (Bug 358020) in and around selection changes in views.

I don't have reproducible steps yet but I had been using the Commit view, History view, and others.
Comment 1 Remy Suen CLA 2011-11-17 14:40:12 EST 
DJ, if this happens to you again, try 'Window > New Window' and see if the problem occurs in the new window. Thanks.
Comment 2 Eric Moffatt CLA 2011-11-24 11:27:33 EST 
Just encountered this while trying 'Compare with HEAD'...truly strange since it ended up comparing the UIElement.ecore file which I haven't even had open for weeks...

BTW, I did a Window -> New Window and it seems to be sane again (this is still scarey, 3.x users who encounter this will question the stability of 4.x in general IMO).
Comment 3 Paul Webster CLA 2011-11-24 13:05:14 EST 
Remy, where abouts are their compare with actions/handlers?

PW
Comment 4 Remy Suen CLA 2011-11-24 13:08:37 EST 
(In reply to comment #3)
> Remy, where abouts are their compare with actions/handlers?

Knock yourself out.
http://egit.eclipse.org/w/?p=egit.git;a=tree;f=org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions;hb=HEAD
Comment 5 Remy Suen CLA 2011-11-28 16:23:29 EST 
Just got hit by this bug with I20111124-2200 on Windows 7.
Comment 6 Remy Suen CLA 2011-11-30 10:25:47 EST 
1. Make a new untracked file.
2. Open the 'Git Staging' view.
3. Select the file > Context menu > Replace with File in Git Index.
4. Nothing happens. I would argue this is a bug in EGit.
5. Go try and use 'Compare With' on another file now. The selection has now been locked.
Comment 7 Remy Suen CLA 2011-11-30 10:28:21 EST 
getActiveMenuSelection(*) returns the old selection.

getCurrentSelectionChecked(*) returns the correct selection.
Comment 8 Remy Suen CLA 2011-11-30 10:44:38 EST 
Fix released to master. Thanks for the bug report, DJ.
http://git.eclipse.org/c/platform/eclipse.platform.ui.git/commit/?id=ad263d22eba32dcd7eb2b1b2cf4b6450f9769abb

Trace of EGit calling getCurrentState().

Thread [main] (Suspended (breakpoint at line 556 in LegacyHandlerService))	
	LegacyHandlerService.getCurrentState() line: 556	
	StagingView.createItem(String, TableViewer) line: 898	
	StagingView.access$23(StagingView, String, TableViewer) line: 889	
	StagingView$21.menuAboutToShow(IMenuManager) line: 850	
	MenuManager.fireAboutToShow(IMenuManager) line: 342	
	MenuManager.handleAboutToShow() line: 473	
	MenuManager.access$1(MenuManager) line: 469	
	MenuManager$2.menuShown(MenuEvent) line: 495	
	TypedListener.handleEvent(Event) line: 247	
	EventTable.sendEvent(Event) line: 84	
	Menu(Widget).sendEvent(Event) line: 1053	
	Menu(Widget).sendEvent(int, Event, boolean) line: 1077	
	Menu(Widget).sendEvent(int) line: 1058	
	Shell(Control).WM_INITMENUPOPUP(long, long) line: 4881	
	Shell(Control).windowProc(long, int, long, long) line: 4557	
	Shell(Canvas).windowProc(long, int, long, long) line: 341	
	Shell(Decorations).windowProc(long, int, long, long) line: 1627	
	Shell.windowProc(long, int, long, long) line: 2069	
	Display.windowProc(long, long, long, long) line: 4972	
	OS.TrackPopupMenu(long, int, int, int, int, long, RECT) line: not available [native method]	
	Menu._setVisible(boolean) line: 256	
	Display.runPopups() line: 4206	
	Display.readAndDispatch() line: 3748	
	PartRenderingEngine$9.run() line: 977
Comment 9 Paul Webster CLA 2011-11-30 13:49:12 EST 
I had a look at the code for org.eclipse.egit.ui.internal.staging.StagingView.createItem(String, TableViewer)

They're just setting a variable into the context and hoping that will be the correct thing when a user executes their view.  They have a race condition with any other SWT events that might change the selection, although it probably works ... mostly.

PW
Comment 10 Remy Suen CLA 2011-12-06 13:45:40 EST 
(In reply to comment #6)
> 1. Make a new untracked file.
> 2. Open the 'Git Staging' view.
> 3. Select the file > Context menu > Replace with File in Git Index.
> 4. Nothing happens. I would argue this is a bug in EGit.
> 5. Go try and use 'Compare With' on another file now. The selection has now
> been locked.

The incorrect behaviour cannot be reproduced and the 'Git Staging' view appears to continue to function properly with I20111205-2330 on Windows 7.

DJ, let me know if you see this again.