[vlc-devel] [PATCH] contrib: ass: Add patch to fix crash on macOS

[Marvin Scholz]

Fixes a segfault in libass get_font_file function due to
insufficient checks of return values.
---
 contrib/src/ass/coretext-errorhandling.patch | 27 ++++++++++++++++++++
 contrib/src/ass/rules.mak                    |  1 +
 2 files changed, 28 insertions(+)
 create mode 100644 contrib/src/ass/coretext-errorhandling.patch

diff --git a/contrib/src/ass/coretext-errorhandling.patch b/contrib/src/ass/coretext-errorhandling.patch
new file mode 100644
index 0000000000..29401e48dc
--- /dev/null
+++ b/contrib/src/ass/coretext-errorhandling.patch
@@ -0,0 +1,27 @@
+diff --git a/libass/ass_coretext.c b/libass/ass_coretext.c
+index 59a8a2d..7371f7c 100644
+--- a/libass/ass_coretext.c
++++ b/libass/ass_coretext.c
+@@ -96,7 +96,13 @@ static bool check_glyph(void *priv, uint32_t code)
+ static char *get_font_file(CTFontDescriptorRef fontd)
+ {
+     CFURLRef url = CTFontDescriptorCopyAttribute(fontd, kCTFontURLAttribute);
++    if (!url)
++        return NULL;
+     CFStringRef path = CFURLCopyFileSystemPath(url, kCFURLPOSIXPathStyle);
++    if (!path) {
++        SAFE_CFRelease(url);
++        return NULL;
++    }
+     char *buffer = cfstr2buf(path);
+     SAFE_CFRelease(path);
+     SAFE_CFRelease(url);
+@@ -133,7 +139,7 @@ static void process_descriptors(ASS_Library *lib, ASS_FontProvider *provider,
+         int index = -1;
+ 
+         char *path = get_font_file(fontd);
+-        if (strcmp("", path) == 0) {
++        if (!path || strcmp("", path) == 0) {
+             // skip the font if the URL field in the font descriptor is empty
+             free(path);
+             continue;
diff --git a/contrib/src/ass/rules.mak b/contrib/src/ass/rules.mak
index 1849987447..364afbad17 100644
--- a/contrib/src/ass/rules.mak
+++ b/contrib/src/ass/rules.mak
@@ -43,6 +43,7 @@ $(TARBALLS)/libass-$(ASS_VERSION).tar.gz:
 libass: libass-$(ASS_VERSION).tar.gz .sum-ass
 	$(UNPACK)
 	$(APPLY) $(SRC)/ass/ass-macosx.patch
+	$(APPLY) $(SRC)/ass/coretext-errorhandling.patch
 ifdef HAVE_WIN32
 	$(APPLY) $(SRC)/ass/use-topendir.patch
 	$(APPLY) $(SRC)/ass/libass-no-tchar.patch
-- 
2.20.1 (Apple Git-117)