pdfviewer: don't crash if the xref is corrupted.

Review URL: https://codereview.chromium.org/20004007

git-svn-id: http://skia.googlecode.com/svn/trunk@10293 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 9 insertions, 0 deletions

diff --git a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
index 4798031808..cc5788bfd7 100644
--- a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
+++ b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
@@ -291,6 +291,9 @@ static int readStringLength(int level, const unsigned char* start, const unsigne
 }
 
 static const unsigned char* readString(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* str, SkPdfAllocator* allocator) {
+    if (!allocator) {
+        return end;
+    }
     int outLength = readStringLength(level, start, end);
     // TODO(edisonn): optimize the allocation, don't allocate new string, but put it in a preallocated buffer
     unsigned char* out = (unsigned char*)allocator->alloc(outLength);
@@ -434,6 +437,9 @@ static int readHexStringLength(int level, const unsigned char* start, const unsi
 }
 
 static const unsigned char* readHexString(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* str, SkPdfAllocator* allocator) {
+    if (!allocator) {
+        return end;
+    }
     int outLength = readHexStringLength(level, start, end);
     // TODO(edisonn): optimize the allocation, don't allocate new string, but put it in a preallocated buffer
     unsigned char* out = (unsigned char*)allocator->alloc(outLength);
@@ -556,6 +562,9 @@ static int readNameLength(int level, const unsigned char* start, const unsigned
 }
 
 static const unsigned char* readName(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* name, SkPdfAllocator* allocator) {
+    if (!allocator) {
+        return end;
+    }
     int outLength = readNameLength(level, start, end);
     // TODO(edisonn): optimize the allocation, don't allocate new string, but put it in a preallocated buffer
     unsigned char* out = (unsigned char*)allocator->alloc(outLength);