59668 - Occurences of uninitialized variables being used before being set (gfx/src)

Status: RESOLVED WORKSFORME

(Core :: Layout, defect, P3)

Description

[Rich Burridge]

For more details on this problem, see:

http://bugzilla.mozilla.org/show_bug.cgi?id=59652

This bug is just for the warnings in various source files in the GTK
Embedding Widget module:

nsBlender.cpp:267: warning: `PRUint32 srccolor' might be used uninitialized in
this function
nsBlender.cpp:267: warning: `PRUint32 secsrccolor' might be used uninitialized
in this function
nsBlender.cpp:354: warning: `PRUint32 srccolor' might be used uninitialized in
this function
nsBlender.cpp:354: warning: `PRUint32 secsrccolor' might be used uninitialized
in this function
nsBlender.cpp:449: warning: `PRUint16 srccolor' might be used uninitialized in
this function
nsBlender.cpp:449: warning: `PRUint16 secsrccolor' might be used uninitialized
in this function
----
nsFontMetricsGTK.cpp:2112: warning: `class nsFontGTK * p' might be used
uninitialized in this function
----
nsGfxFactoryGTK.cpp:60: warning: `class nsIScriptableRegion * inst' might be
used uninitialized in this function
----
nsImageGTK.cpp:589: warning: `unsigned int pix' might be used uninitialized in
this function
../../../dist/include/nsAReadableString.h:1085: warning: `int whichString' might
be used uninitialized in this function
----

Comment 1

[Asa Dotzler [:asa]]

Bugs targeted at mozilla1.0 without the mozilla1.0 keyword moved to mozilla1.0.1 
(you can query for this string to delete spam or retrieve the list of bugs I've 
moved)

Comment 2

[Aleksey Nogin]

Currently ( http://tinderbox.mozilla.org/SeaMonkey/warn1013026020.23864.html -
Wed, 06 Feb 2002 15:07) gfx/src has the following warnings:

gfx/src/gtk/nsFontMetricsGTK.cpp:2950
 `class nsFontGTK * p' might be used uninitialized in this function

gfx/src/gtk/nsGfxFactoryGTK.cpp:91
 `class nsIScriptableRegion * inst' might be used uninitialized in this function

gfx/src/gtk/nsImageGTK.cpp:1855
 `PRUint32 alphaStride' might be used uninitialized in this function

gfx/src/gtk/nsImageGTK.cpp:942
 `unsigned int pix' might be used uninitialized in this function

gfx/src/x11shared/nsXFontAAScaledBitmap.cpp:318
 `struct XChar2b * aChar2b' might be used uninitialized in this function

Comment 3

[Aleksey Nogin]

There are only two such warnings left in gfx/src:

1)
gfx/src/gtk/nsGfxFactoryGTK.cpp:91
 `class nsIScriptableRegion * inst' might be used uninitialized in this function

There and uninitialized pointer will be compared to null in rgn is null (this
code was checked in by Blizzard).

2)
gfx/src/gtk/nsImageGTK.cpp:942
 `unsigned int pix' might be used uninitialized in this function

Here, if ximage->bits_per_pixel turns out to be nonsense (e.g. not one of 1, 4,
8, 16, 24 or 32), unpredicatble random things will start happening...

P.S. Trying to make 1.0 as warnings-free as possible...

Comment 4

[Aleksey Nogin]

Not sure how gfx and gfx2 are related, but here is another one of those:

3)
gfx2/src/gfxImageFrame.cpp:72
 `enum nsMaskRequirements maskReq' might be used uninitialized in this function

There if gfxImageFrame::Init is called with unsupported gfx_format, then
mImage->Init will be called with uninitialized nsMaskRequirements

Comment 5

[Atul Aggarwal]

The only error which remains in gfx/src (using gcc 4.6.1 on linux) is 
mozilla-central/gfx/src/nsDeviceContext.cpp:829:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]

Comment 6

[Atul Aggarwal]

Hence closing this bug as uninitialized errors does not exists in gfx/src.