MySQL Bugs: #68444: MySQL Workbench no longer allows opening multiple instances of Workbench

Bug #68444	MySQL Workbench no longer allows opening multiple instances of Workbench
Submitted:	20 Feb 2013 18:40	Modified:	26 Feb 2013 16:11
Reporter:	BJ Quinn	Email Updates:
Status:	Can't repeat	Impact on me:	None
Category:	MySQL Workbench	Severity:	S2 (Serious)
Version:	5.2.47	OS:	Windows
Assigned to:		CPU Architecture:	Any

Description:
MySQL Workbench seems to no longer allow opening multiple instances of the program. This was allowed at least as recently as 5.2.40, and appears to have been disabled at least with versions 5.2.45-5.2.47. I've seen a few mentions on forum postings, etc. that the reason for this was to avoid conflicts with multiple instances of Workbench operating on the same model file or something like that. I've used multiple instances of Workbench for years and never had any issues, and have no intention of opening the same model file twice. I do, however, have two screens, and I frequently use multiple copies of Workbench so that I can see more than one thing at a time. The tabs feature is nice, but doesn't allow you to see multiple things at a time. Seems like the solution would be to check to see if the model file is already open, or to lock the file or something, rather than to disable opening multiple instances for the many non-dangerous uses of that feature. Also, going back to earlier versions, I remember that for a version somewhere around 5.2.3x, this was allowed, and got disabled, and then allowed again. Seems to have gotten disabled again around 5.2.45.

How to repeat:
Click on the MySQL Workbench icon to open the program. MySQL Workbench opens. Click on it again. 2nd copy of Workbench no longer opens in newer versions.

Suggested fix:
If the concern is multiple copies of workbench accessing the same model file, lock the file. If the concern is auto-save, disable auto-save for instances beyond the first one or something. Don't disable having multiple copies of workbench open for all the many legitimate uses of this feature.

I can confirm after having tried each version from 5.2.47 down to 5.2.40 that 5.2.40 is the last version to allow multiple instances.  The change appears to have happened in 5.2.41.

two instances

Attachment: two_instances.png (image/png, text), 289.73 KiB.

Please see attached screen-shot. Thanks.

What version is that?  Are you doing anything special to accomplish that?  When I have 5.2.41+, if I right click on the icon in the task bar and click "MySQL Workbench", it simply highlights the already-open instance's task bar icon yellow and doesn't open a new instance.  If I click on the start menu icon, same thing.  Re-installing 5.2.40 allows both of those methods to open a second instance.  Once I install 5.2.41+, I can't do it anymore (that way at least, and I don't know of any other way).  Since filing the bug, I've confirmed the problem on three different computers.  One Win7 64-bit, one Win7 32-bit, and one WinXP.