Re: ports/122924: XCreateImage fails in most recent x11/XOrg

[Dorr H. Clark]

Bug Number 122924: XcreateImage fails in most recent x11/XOrg

This is actually not a bug in FreeBSD, in fact during the investigation
of this bug we were able to reproduce it on Linux (although at a higher
level).

To resolve a bug in XOrg file, we need to have the source files for XOrgalong
with the mandatory external dependencies.  Code changes have been made in file
ImUtil.c in directory /usr/ports/distfiles/xorg/lib/libX11-1.1.3/src
and at the bottom of this writeup is an explanation of how to retrieve
the software needed for investigating this bug.

The function XCreateImage takes image_bytes_per_line as one of the inputs.
This parameter determines the value for Number of bytes between a pixel
on one line and the pixel with the same X coordinate on the next line.
In case the calling function sets this parameter to 0, XCreateImage
calculates the minimum value for image_bytes_per_line depending upon
the format of image and the required depth.
Thus, if the input value for image_bytes_per_line is zero or less than
the minimum value, it is set equal to the minimum value.

Here is the patch:

--- ImUtil_org.c 2008-08-21 12:46:15.000000000 +0000
+++ ImUtil.c 2008-08-21 12:47:37.000000000 +0000
@@ -372,10 +372,8 @@
     min_bytes_per_line =
         ROUNDUP((width + offset), image->bitmap_pad);
  }
- if (image_bytes_per_line == 0 ) {
+ if (image_bytes_per_line == 0 ||image_bytes_per_line < min_bytes_per_line  ) {
     image->bytes_per_line = min_bytes_per_line;
- } else if (image_bytes_per_line < min_bytes_per_line) {
- return 0;
  }
  else {
     image->bytes_per_line = image_bytes_per_line;


Shikha Bansal , engineer
Dorr H. Clark, advisor
Graduate School of Engineering
Santa Clara University,
Santa Clara CA

http://www.cse.scu.edu/~dclark/coen_284_FreeBSD/122924.txt

1) GET THE XORG SOURCES
        a) cd /usr/ports/x11/xorg
        b) make (you must be connected to internet)
   This copies the source files into /usr/ports/distfiles

2) GET THE EXTERNAL DEPENDENCIES
        a) go to xcb.freedesktop.org/dist/
        b) Download libxcb-0.9.93.tar.gz and xcb-proto-0.9.93.tar.gz in directory /usr/ports/distfiles/xorg/lib
        c) cd xcb-proto-0.9.93
        d) make
        e) cp *.pc /usr/local/libdata/pkgconfig
        f) make install
        g) similarly install libxcb-0.9.93

3)  INSTALL XORG AS A PORT
        a) cd /usr/ports/distfiles/xorg/lib/libX11-1.1.3/include
        b) mkdir xcb
        c) copy the following 4 headers from libxcb-0.9.93 to xcb folder created in previous step:
        xcb.h,xproto.h,xcbext.h,xcblib.h
        d) make install

 




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