1486385 - SkPDFConvertType1FontStream.cpp uses isxdigit()

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect, P3)

Description

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2025-12-29)]

SkPDFConvertType1FontStream.cpp uses isxdigit(). This has 2 bugs:

1) On platforms where char is signed, calling isxdigit() with a char argument is UB when the most-significant bit of the char is set.

2) According to MSDN, isxdigit() is locale-sensitive. According to glibc sources, isxdigit() does a lookup from locale-dependent tables, but I didn't check if the that part of the tables actually varies by locale.

Instead of using isxdigit(), Skia should have a function that does
('0' <= c && c <= '9') || ('A' <= c && c <= 'f') || ('A' <= c && c <= 'F')

Comment 1

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2025-12-29)]

Filed upstream issue:
https://bugs.chromium.org/p/skia/issues/detail?id=8285

Comment 2

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2025-12-29)]

(In reply to Henri Sivonen (:hsivonen) from comment #0)
> ('0' <= c && c <= '9') || ('A' <= c && c <= 'f') || ('A' <= c && c <= 'F')

'a' instead of 'A' the first time.

Comment 3

[Andrew Osmond [:aosmond] (he/him)]

Lee, I assume this will be picked up by a future skia update?

Comment 4

[Jake Senne]

This bug has been patched in upstream and merged here. This bug should be closed.