Fix some -Wmaybe-uninitialized errors.

Fix some -Wmaybe-uninitialized errors.

- Break up CPDF_DIBSource::DownSampleScanline() into smaller functions.

R=tsepez@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/9ae9ae2a68439cbc84a719c0dacf6984703e77cb

[Lei Zhang, 2015-08-18 20:10:31]

thestig@chromium.org changed reviewers:
+ tsepez@chromium.org

[Lei Zhang, 2015-08-18 20:10:32]

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_edit/...
File core/src/fpdfapi/fpdf_edit/fpdf_edit_image.cpp (right):

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_edit/...
core/src/fpdfapi/fpdf_edit/fpdf_edit_image.cpp:221: FX_STRSIZE mask_size = 0;
_DCTEncodeBitmap() and _JBIG2EncodeBitmap() are no-ops, so they don't initialize
|mask_size|. Better off giving it a sane value.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
File core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp (right):

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1300:
DownSampleScanline1Bit(orig_Bpp, dest_Bpp, src_width, pSrcLine, dest_scan,
I basically moved each block into its own function as a starting point in
untangling this code.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1464: FX_ARGB last_argb =
FXARGB_MAKE(0xFF, 0xFF, 0xFF, 0xFF);
Init |last_argb| here.

https://codereview.chromium.org/1287843004/diff/1/core/src/fxge/ge/fx_ge_font...
File core/src/fxge/ge/fx_ge_fontmap.cpp (right):

https://codereview.chromium.org/1287843004/diff/1/core/src/fxge/ge/fx_ge_font...
core/src/fxge/ge/fx_ge_fontmap.cpp:1474: if (GET_TT_LONG(p) == table) {
|offset| may not be initialized

[Tom Sepez, 2015-08-18 20:20:50]

lgtm

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
File core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp (right):

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:787: MatteColor =
0xFFFFFFFF;
nit: not sure why you felt compelled to change this, but no matter.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:815: m_MatteColor =
0XFFFFFFFf;
nit: last F is f.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1249: return m_pDecoder ?
m_pDecoder->SkipToScanline(line, pPause) : FALSE;
nit: m_pDecoder && m_pDecoder->SkipToScanline(line, pPause);

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1259: if (line < 0 ||
dest_scan == nullptr || dest_bpp <= 0 || dest_width <= 0 ||
nit: !dest_scan

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1320: FX_DWORD set_argb =
(FX_DWORD)-1, reset_argb = 0;
nit: one per line.

https://codereview.chromium.org/1287843004/diff/1/core/src/fxge/ge/fx_ge_font...
File core/src/fxge/ge/fx_ge_fontmap.cpp (right):

https://codereview.chromium.org/1287843004/diff/1/core/src/fxge/ge/fx_ge_font...
core/src/fxge/ge/fx_ge_fontmap.cpp:1474: if (GET_TT_LONG(p) == table) {
On 2015/08/18 20:10:32, Lei Zhang wrote:
> |offset| may not be initialized
Ok, probably an error to continue if one of the above paths not taken, but
nevermind.

[Lei Zhang, 2015-08-20 21:43:41]

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
File core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp (right):

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:787: MatteColor =
0xFFFFFFFF;
On 2015/08/18 20:20:50, Tom Sepez (Out Aug 20-29) wrote:
> nit: not sure why you felt compelled to change this, but no matter.

I like them in caps.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:815: m_MatteColor =
0XFFFFFFFf;
On 2015/08/18 20:20:50, Tom Sepez (Out Aug 20-29) wrote:
> nit: last F is f.

fail

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1249: return m_pDecoder ?
m_pDecoder->SkipToScanline(line, pPause) : FALSE;
On 2015/08/18 20:20:50, Tom Sepez (Out Aug 20-29) wrote:
> nit: m_pDecoder && m_pDecoder->SkipToScanline(line, pPause);

Done.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1259: if (line < 0 ||
dest_scan == nullptr || dest_bpp <= 0 || dest_width <= 0 ||
On 2015/08/18 20:20:50, Tom Sepez (Out Aug 20-29) wrote:
> nit: !dest_scan

Done.

https://codereview.chromium.org/1287843004/diff/1/core/src/fpdfapi/fpdf_rende...
core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp:1320: FX_DWORD set_argb =
(FX_DWORD)-1, reset_argb = 0;
On 2015/08/18 20:20:50, Tom Sepez (Out Aug 20-29) wrote:
> nit: one per line.

Done.

[Lei Zhang, 2015-08-20 21:43:48]

Committed patchset #2 (id:20001) manually as
9ae9ae2a68439cbc84a719c0dacf6984703e77cb (presubmit successful).