Fix potentially uninitialized value.
Depending on what ReadOK does it's possible for |dircount16| to be used without
being initialized. The read code calls back into PDFium specific code which then
calls into the stream reading code.
Initialize the value to be sure it is set.
BUG=chromium:651632
Review-Url: https://codereview.chromium.org/2389993002
diff --git a/third_party/libtiff/0007-uninitialized-value.patch b/third_party/libtiff/0007-uninitialized-value.patch
new file mode 100644
index 0000000..f6e9806
--- /dev/null
+++ b/third_party/libtiff/0007-uninitialized-value.patch
@@ -0,0 +1,13 @@
+diff --git a/third_party/libtiff/tif_dirread.c b/third_party/libtiff/tif_dirread.c
+index 5ef3264..bc41021 100644
+--- a/third_party/libtiff/tif_dirread.c
++++ b/third_party/libtiff/tif_dirread.c
+@@ -4443,7 +4443,7 @@ TIFFFetchDirectory(TIFF* tif, uint64 diroff, TIFFDirEntry** pdir,
+ static const char module[] = "TIFFFetchDirectory";
+
+ void* origdir;
+- uint16 dircount16;
++ uint16 dircount16 = 0;
+ uint32 dirsize;
+ TIFFDirEntry* dir;
+ uint8* ma;
diff --git a/third_party/libtiff/README.pdfium b/third_party/libtiff/README.pdfium
index 936cd94..2f9c4f9 100644
--- a/third_party/libtiff/README.pdfium
+++ b/third_party/libtiff/README.pdfium
@@ -16,3 +16,4 @@
0004-CVE-2015-8784.patch: Security fixes
0005-Leak-TIFFFetchStripThing.patch: Fix a memory leak
0006-HeapBufferOverflow-ChopUpSingleUncompressedStrip.patch: Fix a heap buffer overflow
+0007-uninitialized-value.patch: Fix potentially uninitialized dircount value
diff --git a/third_party/libtiff/tif_dirread.c b/third_party/libtiff/tif_dirread.c
index 5ef3264..bc41021 100644
--- a/third_party/libtiff/tif_dirread.c
+++ b/third_party/libtiff/tif_dirread.c
@@ -4443,7 +4443,7 @@
static const char module[] = "TIFFFetchDirectory";
void* origdir;
- uint16 dircount16;
+ uint16 dircount16 = 0;
uint32 dirsize;
TIFFDirEntry* dir;
uint8* ma;
