[cairo-commit] 2 commits - src/cairo-pdf-surface.c
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Sun Feb 21 15:49:07 UTC 2021
src/cairo-pdf-surface.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
New commits:
commit f4e43b6822ec73f2fd8046859315e5d2a5709bf5
Merge: 79b539fab a3b69a021
Author: Heiko Lewin <hlewin at gmx.de>
Date: Sun Feb 21 15:49:06 2021 +0000
Merge branch 'pdf-font-names' into 'master'
pdf font subset: Generate valid font names
Closes #449
See merge request cairo/cairo!125
commit a3b69a0215fdface0fd5730872a4b3242d979dca
Author: Uli Schlachter <psychon at znc.in>
Date: Tue Feb 9 16:54:35 2021 +0100
pdf font subset: Generate valid font names
A hash value is encoded in base 26 with upper case letters for font
names.
Commit ed984146 replaced "numerator = abs (hash);" with "numerator =
hash;" in this code, because hash has type uint32_t and the compiler
warned about taking the absolute value of an unsigned value. However,
abs() is actually defined to take an int argument. Thus, there was some
implicit cast.
Since numerator has type long, i.e. is signed, it is now actually
possible to get an overflow in the implicit cast and then have a
negative number. The following code is not prepared for this and
produces non-letters when encoding the hash.
This commit fixes that problem by not using ldiv() and instead using /
and % to directly compute the needed values. This gets rid of the need
to convert to type long. Since now everything works with uint32_t, there
is no more chance for negative numbers messing things up.
Fixes: https://gitlab.freedesktop.org/cairo/cairo/-/issues/449
Signed-off-by: Uli Schlachter <psychon at znc.in>
diff --git a/src/cairo-pdf-surface.c b/src/cairo-pdf-surface.c
index 6da460878..52c49b6d2 100644
--- a/src/cairo-pdf-surface.c
+++ b/src/cairo-pdf-surface.c
@@ -5310,18 +5310,14 @@ _create_font_subset_tag (cairo_scaled_font_subset_t *font_subset,
{
uint32_t hash;
int i;
- long numerator;
- ldiv_t d;
hash = _hash_data ((unsigned char *) font_name, strlen(font_name), 0);
hash = _hash_data ((unsigned char *) (font_subset->glyphs),
font_subset->num_glyphs * sizeof(unsigned long), hash);
- numerator = hash;
for (i = 0; i < 6; i++) {
- d = ldiv (numerator, 26);
- numerator = d.quot;
- tag[i] = 'A' + d.rem;
+ tag[i] = 'A' + (hash % 26);
+ hash /= 26;
}
tag[i] = 0;
}
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