[Bug awt/27239] New: Images shown with wrong color on powerpc (big endian)

[bernhard at intevation dot de]

Failure, observed:
        Images from the go stones and avatars have the wrong colors
        for the go applets from games.yahoo.com/go

        Especially the black stones are almost invisible and there is
        a white transparancy when they are displayed.

Observations:
                This works on ia86 (little endian),
                but not on ppc (big endian).

                The bug can be seen with jamvm 1.4.2
                classpath-0.90 with Mouse events patch from
http://cvs.savannah.gnu.org/viewcvs/classpath/classpath/java/awt/LightweightDispatcher.java.diff?tr1=1.2&tr2=1.3&r1=text&r2=text


        Hypothesis: A bug in the image handling code regarding endianess.

Meanwhile I could reproduce this with the testcase
        from http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24116

I will attach a screenshot.
The test case uses different methods to draw the image.
As not all tiles have wrong colors, possibly only one methods is broken.

Further ideas, attempts:
Search for
        find native/jni/gtk-peer  -name "*.c" | xargs grep -i "<<"
        find native/jni/gtk-peer  -name "*.c" | xargs grep -i ">>"

        finds bitshifts in
                gnu_java_awt_peer_gtk_GdkPixbufDecoder.c
                gnu_java_awt_peer_gtk_GdkGraphics.c
                gnu_java_awt_peer_gtk_GtkImage.c
                gnu_java_awt_peer_gtk_GtkToolkit.c

        A look in gnu_java_awt_peer_gtk_GdkPixbufDecoder.c reveals that
        there are comments about the endianess.

        grep -i endian *
        finds mentions in
                gnu_java_awt_peer_gtk_GdkPixbufDecoder.c
                gnu_java_awt_peer_gtk_GdkRobotPeer.c

        Inspection in gnu_java_awt_peer_gtk_GdkPixbufDecoder.c shows
        that Java_gnu_java_awt_peer_gtk_GdkPixbufDecoder_streamImage()

        smells as there is a comment that RGB is in host memory order,
        but no special handling regarding endianess.


-- 
           Summary: Images shown with wrong color on powerpc (big endian)
           Product: classpath
           Version: 0.90
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: awt
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bernhard at intevation dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27239