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Bug 1220831 - plotyy crashes octave due to problem in the default graphics engine (FLTK)
Summary: plotyy crashes octave due to problem in the default graphics engine (FLTK)
Status: CLOSED DUPLICATE of bug 1218360
Alias: None
Product: Fedora
Classification: Fedora
Component: octave
Version: 21
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
Assignee: Jaromír Cápík
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2015-05-12 14:56 UTC by Przemek Klosowski
Modified: 2016-02-01 02:01 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2015-05-12 15:50:56 UTC
Type: Bug

Attachments (Terms of Use)

Description Przemek Klosowski 2015-05-12 14:56:26 UTC
Description of problem:
plotyy crashes octave due to problem in the default graphics engine (FLTK)

Version-Release number of selected component (if applicable):

How reproducible: every time

Steps to Reproduce:
1. run octave
2. x=1:10; plotyy(x,x,x,x);

Actual results: Octave crashes with SEGV

Expected results: Octave does not crash and displays a graph

Comment 1 Przemek Klosowski 2015-05-12 14:57:18 UTC
This is caused by FLTK because 


works fine and gives expected plot

Comment 2 Przemek Klosowski 2015-05-12 15:02:04 UTC
The crash is caused by a corrupted 'overlay' variable  in Fl_Gl_Window::show (this=0xd0e180) at Fl_Gl_Window.cxx:87 :

 if (overlay && overlay != this) ((Fl_Gl_Window*)overlay)->show();

p overlay
$1 = (void *) 0x3ff0000000000000

p *(Fl_Gl_Window*)overlay
Cannot access memory at address 0x3ff0000000000000

Comment 3 Przemek Klosowski 2015-05-12 15:07:26 UTC
Just for completeness, I have fltk-1.3.3-2.fc21.x86_64

Comment 4 Orion Poplawski 2015-05-12 15:50:56 UTC

*** This bug has been marked as a duplicate of bug 1218360 ***

Comment 5 Przemek Klosowski 2015-05-12 15:56:32 UTC
There seems to be a problem with the multiple definition of overlay. When Octave crashes, overlay as seen in the crashing leaf procedure Fl_Gl_Window::show is corrupted to (void *) 0x3ff0000000000000 (see comment 2), but up in the call stack it is different: 

 #1  0x00007fffeef98a90 in Fl_Window::handle (this=this@entry=0xcd7f30, 
    ev=ev@entry=16) at Fl.cxx:1613

p overlay
  $6 = {int (const WINDOW *, WINDOW *)} 0x330a6121e0 <overlay>

which happens to be identical to the definition of overlay just after Octave starts.

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