bugGNU Octave - Bugs: bug #50396, documentation tab in GUI empty


bug #50396: documentation tab in GUI empty

Submitted by:  A.R. Burgers <arb>
Submitted on:  Fri 24 Feb 2017 10:40:15 PM UTC  
Category: DocumentationSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Regression
Status: FixedAssigned to: None
Originator Name: Open/Closed: Closed
Release: devOperating System: Any

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Tue 02 May 2017 09:51:41 PM UTC, comment #8:

Verified fix. Closing report.

Rik <rik5>
Project Administrator
Tue 02 May 2017 09:49:58 PM UTC, comment #7:

I pushed this changeset:


Does it fix the problem for you? The change is to initialize the global variables in the application object instead of the interpreter object. That way, Vinfo_file is available for the GUI initialization.

There are about 50 global variables like Vinfo_file. Many are given default values by the call to install_defaults. Eventually, I'd like to move variables like this to be members of the application or interpreter object, whichever is more appropriate for each of them.

John W. Eaton <jwe>
Project Administrator
Mon 27 Feb 2017 04:29:02 PM UTC, comment #6:

The patch in comment #5 will do for a workaround on Windows, but Linux and Mac users still have a problem. They can temporarily use the fix in comment #2 that I suggested. Long term, this needs to be fixed properly so it works reliably everywhere.

Rik <rik5>
Project Administrator
Mon 27 Feb 2017 12:48:20 PM UTC, comment #5:

Another quick fix, based on Rik's comment #2, would be the attached patch for octave.vbs (in mxe-octave)
That patch seems to work quite fine for me.

(file #39836)

Philip Nienhuis <philipnienhuis>
Project Member
Sun 26 Feb 2017 09:46:18 PM UTC, comment #4:

As a quick hack to verify the race condition I added a "sleep (5);" function call to the constructor in webinfo.cc. Unfortunately, this just delayed the launch of the GUI by 5 seconds, and then the same printf ordering showing the GUI starting before the Octave interpreter thread.

Rik <rik5>
Project Administrator
Sat 25 Feb 2017 08:48:04 PM UTC, comment #3:

I added some print statements and from what I can determine this is an order of execution issue (race condition). The GUI browser for the documentation uses the global variable Vinfo_file which contains the full-path name of the file to use. The code for this is in libgui/src/qtinfo/webinfo.cc. The Octave interpreter sets this global variable in set_info_file_name() which in turn is called by the general initialization function install_defaults().

The problem seems to be the multi-threaded nature of the GUI with one thread for the actual GUI and another thread for the Octave interpreter. When I run the GUI the print statements reveal that the GUI is initializing itself and grabbing the value of Vinfo_file before the Octave interpreter has called install_defaults(). This is likely to be a generic problem because there are other global variables that the GUI uses which reside in the Octave interpreter.

I've added jwe to the CC list since he understands the start-up sequence, including the fork and exec model, better than I do.

Rik <rik5>
Project Administrator
Sat 25 Feb 2017 03:22:41 AM UTC, comment #2:

The problem is that the GUI, not the CLI, is getting a blank name for the info file. As a workaround, you can supply the filename on the command line.

Rik <rik5>
Project Administrator
Fri 24 Feb 2017 11:46:53 PM UTC, comment #1:

Confirmed. The files are there but the GUI does not acknowledge them. By contrast, if I start octave with --no-gui and use the CLI then the info files are available. The correct location is used--I checked by using the info_file() command.

Rik <rik5>
Project Administrator
Fri 24 Feb 2017 10:40:15 PM UTC, original submission:

When I install current dev versions, and go the documentation tab in the GUI, the documentation tab show this message:

In my 4.2.0 installation the documentation tab works as expected.

A.R. Burgers <arb>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach File(s):

Attached Files
file #39836:  bug50396_mxe_doc.patch added by philipnienhuis (520B - application/octet-stream)


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -unavailable- added by jwe (Posted a comment)
  • -unavailable- added by rik5
  • -unavailable- added by rik5 (Posted a comment)
  • -unavailable- added by arb (Submitted the item)

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    Follow 7 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Tue 02 May 2017 09:51:41 PM UTCrik5StatusReady For Test=>Fixed
    Tue 02 May 2017 09:49:58 PM UTCjweStatusConfirmed=>Ready For Test
    Mon 27 Feb 2017 12:48:20 PM UTCphilipnienhuisAttached File-=>Added bug50396_mxe_doc.patch, #39836
    Sat 25 Feb 2017 08:48:04 PM UTCrik5Carbon-Copy-=>Added jwe
    Fri 24 Feb 2017 11:46:53 PM UTCrik5Item GroupInstallation Failure=>Regression

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