The core of the problem is that the system is asked to lookup the metrics for a character with id == 0. This causes a hit in the fCharToGlyphHash matching the sentinel glyph. This happens because fCharToGlpyhHash is initialized with all zeros, therefore, the fID is zero matching the char with id == 0. The fAdvanceX field of the sentinel glyph is in fact not initialized.
The bigger question is now did a zero character get passed to getUnicharMetrics?
The breaking code is basically as follows:
wchar_t glyph = L'S';
paint.measureText(&glyph, 2);
This get mischaracterized as a utf8 string instead of a utf16(?) string. Because of the little endian ordering, this is the character string 'L' '\0'. Since the size of the original string is two bytes (but a single character) the '\0' is treated as its own character and past to getUnicharMetrics.
TEST:
On windows failed using DrMemory. With this change does not fail.
BUG=463204
Review URL: https://codereview.chromium.org/977063002
This fixes every case where virtual and SK_OVERRIDE were on the same line,
which should be the bulk of cases. We'll have to manually clean up the rest
over time unless I level up in regexes.
for f in (find . -type f); perl -p -i -e 's/virtual (.*)SK_OVERRIDE/\1SK_OVERRIDE/g' $f; end
BUG=skia:
Review URL: https://codereview.chromium.org/806653007
Allow GM results to be compared across machines and platforms by
standardizing the fonts used by all tests.
This adds runtime flags to DM to use either the system font context (the
default), the fonts in the resources directory ( --resourceFonts ) or a set
of canonical paths generated from the fonts ( --portableFonts ).
This CL should leave the current DM results unchanged by default.
If the portable font data or resource font is missing when DM is run, it
falls back to using the system font context.
The create_test_font tool generates the paths and metrics read by DM
with the --portableFonts flag set, and generates the font substitution
tables read by DM with the --resourceFonts flag set.
If DM is run in SkDebug mode with the --reportUsedChars flag set, it
generates the corresponding data compiled into the create_test_font tool.
All GM tests set their typeface information by calling either
sk_tool_utils::set_portable_typeface or
sk_tool_utils::portable_typeface .
(The former takes the paint, the latter returns a SkTypeface.) These calls
can be removed in the future when the Font Manager can be superceded.
BUG=skia:2687
R=mtklein@google.com
Review URL: https://codereview.chromium.org/407183003
