Always traverse the entire parent chain in Page_getInheritedPageProp (issue 5954)

This enables us to find resources placed on multiple levels of the tree.

Fixes 5954.

src/core/core.js

@@ -14,12 +14,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* globals assert, calculateMD5, Catalog, Dict, error, info, isArray,
-           isArrayBuffer, isName, isStream, isString, createPromiseCapability,
-           Linearization, NullStream, PartialEvaluator, shadow, Stream, Lexer,
-           StreamsSequenceStream, stringToPDFString, stringToBytes, Util, XRef,
-           MissingDataException, Promise, Annotation, ObjectLoader, OperatorList
-           */
+/* globals warn, Dict, isDict, shadow, isArray, Util, StreamsSequenceStream,
+           isStream, NullStream, ObjectLoader, PartialEvaluator, Promise,
+           OperatorList, Annotation, error, assert, XRef, isArrayBuffer, Stream,
+           isString, isName, info, Linearization, MissingDataException, Lexer,
+           Catalog, stringToPDFString, stringToBytes, calculateMD5 */
 
 'use strict';
 
@@ -45,17 +44,33 @@ var Page = (function PageClosure() {
       return this.pageDict.get(key);
     },
 
-    getInheritedPageProp: function Page_inheritPageProp(key) {
-      var dict = this.pageDict;
+    getInheritedPageProp: function Page_getInheritedPageProp(key) {
+      var dict = this.pageDict, valueArray = null, loopCount = 0;
+      var MAX_LOOP_COUNT = 100;
+      // Always walk up the entire parent chain, to be able to find
+      // e.g. \Resources placed on multiple levels of the tree.
+      while (dict) {
         var value = dict.get(key);
-      while (value === undefined) {
-        dict = dict.get('Parent');
-        if (!dict) {
+        if (value) {
+          if (!valueArray) {
+            valueArray = [];
+          }
+          valueArray.push(value);
+        }
+        if (++loopCount > MAX_LOOP_COUNT) {
+          warn('Page_getInheritedPageProp: maximum loop count exceeded.');
           break;
         }
-        value = dict.get(key);
+        dict = dict.get('Parent');
+      }
+      if (!valueArray) {
+        return Dict.empty;
       }
-      return value;
+      if (valueArray.length === 1 || !isDict(valueArray[0]) ||
+          loopCount > MAX_LOOP_COUNT) {
+        return valueArray[0];
+      }
+      return Dict.merge(this.xref, valueArray);
     },
 
     get content() {
@@ -63,14 +78,10 @@ var Page = (function PageClosure() {
     },
 
     get resources() {
-      var value = this.getInheritedPageProp('Resources');
       // For robustness: The spec states that a \Resources entry has to be
-      // present, but can be empty. Some document omit it still. In this case
-      // return an empty dictionary:
-      if (value === undefined) {
-        value = Dict.empty;
-      }
-      return shadow(this, 'resources', value);
+      // present, but can be empty. Some document omit it still, in this case
+      // we return an empty dictionary.
+      return shadow(this, 'resources', this.getInheritedPageProp('Resources'));
     },
 
     get mediaBox() {

src/core/obj.js

@@ -213,6 +213,24 @@ var Dict = (function DictClosure() {
 
   Dict.empty = new Dict(null);
 
+  Dict.merge = function Dict_merge(xref, dictArray) {
+    var mergedDict = new Dict(xref);
+
+    for (var i = 0, ii = dictArray.length; i < ii; i++) {
+      var dict = dictArray[i];
+      if (!isDict(dict)) {
+        continue;
+      }
+      for (var keyName in dict.map) {
+        if (mergedDict.map[keyName]) {
+          continue;
+        }
+        mergedDict.map[keyName] = dict.map[keyName];
+      }
+    }
+    return mergedDict;
+  };
+
   return Dict;
 })();
 

test/pdfs/.gitignore

@@ -24,6 +24,7 @@
 !issue4630.pdf
 !issue5202.pdf
 !issue5280.pdf
+!issue5954.pdf
 !alphatrans.pdf
 !devicen.pdf
 !cmykjpeg.pdf

test/pdfs/issue5954.pdf

@@ -0,0 +1,78 @@
+%PDF-1.4
+%âãÏÓ
+1 0 obj 
+<<
+/Pages 2 0 R
+/Type /Catalog
+>>
+endobj 
+3 0 obj 
+<<
+/Parent 2 0 R
+/Resources 
+<<
+/XObject 
+<<
+>>
+>>
+/MediaBox [0 0 200 50]
+/Type /Page
+/Contents 4 0 R
+>>
+endobj 
+4 0 obj 
+<<
+/Length 41
+>>
+stream
+BT
+10 20 TD
+/F1 20 Tf
+(Issue 5954) Tj
+ET
+
+endstream 
+endobj 
+2 0 obj 
+<<
+/MediaBox [0 0 200 50]
+/Resources 5 0 R
+/Kids [3 0 R]
+/Count 1
+/Type /Pages
+>>
+endobj 
+5 0 obj 
+<<
+/Font 
+<<
+/F1 6 0 R
+>>
+>>
+endobj 
+6 0 obj 
+<<
+/BaseFont /Times-Roman
+/Subtype /Type1
+/Name /F1
+/Type /Font
+/Encoding /WinAnsiEncoding
+>>
+endobj xref
+0 7
+0000000000 65535 f 
+0000000015 00000 n 
+0000000282 00000 n 
+0000000066 00000 n 
+0000000188 00000 n 
+0000000381 00000 n 
+0000000427 00000 n 
+trailer
+
+<<
+/Root 1 0 R
+/Size 7
+>>
+startxref
+537
+%%EOF

test/test_manifest.json

@@ -558,6 +558,13 @@
        "link": false,
        "type": "load"
     },
+    {  "id": "issue5954",
+       "file": "pdfs/issue5954.pdf",
+       "md5": "4f60ec0d9bbeec845b681242b8982361",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "txt2pdf",
        "file": "pdfs/txt2pdf.pdf",
        "md5": "02cefa0f5e8d96313bb05163b2f88c8c",