pdfviewer: more simple fixed to prevent crashes

Review URL: https://codereview.chromium.org/19625008

git-svn-id: http://skia.googlecode.com/svn/trunk@10294 2bbb7eff-a529-9590-31e7-b0007b416f81

3 files changed, 16 insertions, 3 deletions

diff --git a/experimental/PdfViewer/SkPdfRenderer.cpp b/experimental/PdfViewer/SkPdfRenderer.cpp
index 6e86fcb6a5..33798cb343 100644
--- a/experimental/PdfViewer/SkPdfRenderer.cpp
+++ b/experimental/PdfViewer/SkPdfRenderer.cpp
@@ -1949,6 +1949,10 @@ bool SkPdfRenderer::renderPage(int page, SkCanvas* canvas, const SkRect& dst) co
     PdfContext pdfContext(fPdfDoc);
 
     SkPdfNativeTokenizer* tokenizer = fPdfDoc->tokenizerOfPage(page, pdfContext.fTmpPageAllocator);
+    if (!tokenizer) {
+        // TODO(edisonn): report/warning/debug
+        return false;
+    }
 
     pdfContext.fOriginalMatrix = SkMatrix::I();
     pdfContext.fGraphicsState.fResources = fPdfDoc->pageResources(page);
diff --git a/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp b/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
index ac543040b0..4fb7f8895b 100644
--- a/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
+++ b/experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp
@@ -189,9 +189,9 @@ long SkNativeParsedPDF::readTrailer(const unsigned char* trailerStart, const uns
     // TODO(edisonn): use null allocator, and let it just fail if memory
     // needs allocated (but no crash)!
     const unsigned char* current =
-            nextObject(0, trailerStart, trailerEnd, &trailerKeyword, fAllocator, NULL);
+            nextObject(0, trailerStart, trailerEnd, &trailerKeyword, NULL, NULL);
 
-    if (strlen("trailer") != trailerKeyword.len() &&
+    if (!trailerKeyword.isKeyword() || strlen("trailer") != trailerKeyword.len() ||
         strncmp(trailerKeyword.c_str(), "trailer", strlen("trailer")) != 0) {
         // TODO(edisonn): report warning, rebuild trailer from objects.
         return -1;
diff --git a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
index cc5788bfd7..7d8bcb695a 100644
--- a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
+++ b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp
@@ -125,6 +125,11 @@ static const unsigned char* endOfPdfToken(int level, const unsigned char* start,
 
 // last elem has to be ]
 static const unsigned char* readArray(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* array, SkPdfAllocator* allocator, SkNativeParsedPDF* doc) {
+    if (allocator == NULL) {
+        // TODO(edisonn): report/warning error
+        return end;
+    }
+
     TRACE_INDENT(level, "Array");
     while (start < end) {
         // skip white spaces
@@ -208,7 +213,7 @@ static const unsigned char* readString(int level, const unsigned char* start, co
                         break;
 
                     case 'f':
-                        *out = kFF_PdfWhiteSpace;
+                        if (hasOut) { *out = kFF_PdfWhiteSpace; }
                         out++;
                         in += 2;
                         break;
@@ -693,6 +698,10 @@ static const unsigned char* readInlineImageStream(int level, const unsigned char
 }
 
 static const unsigned char* readDictionary(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* dict, SkPdfAllocator* allocator, SkNativeParsedPDF* doc) {
+    if (allocator == NULL) {
+        // TODO(edisonn): report/warning error
+        return end;
+    }
     TRACE_INDENT(level, "Dictionary");
     SkPdfObject::makeEmptyDictionary(dict);