large values of x_add and y_add may rollover an int causing a later
assertion to fail in WebPRescalerExportRow due to fxy_scale incorrectly
being set to 0.
fixes:
src/dsp/rescaler.c:178: void WebPRescalerExportRow(WebPRescaler *const):
Assertion `wrk->src_height == wrk->dst_height && wrk->x_add == 1'
failed.
Bug: chromium:1196480
Change-Id: I2c00f015d61a1257033d8edb1edd4d060d6878b7
This is to prevent resizing to dimension 0
+ added some safety checks about src_width > 0 and src_height > 0
BUG=webp:418
Change-Id: Ic04a53ad26455d80538bc8681882a554fca2a340
this avoids duplicates between these trees and dsp/, e.g., enc/tree.c,
dec/tree.c, making pulling the whole library source tree into one target
possible
BUG=webp:279
Change-Id: I060a614833c7c24ddd37bf641702ae6a5eef1775