Support Blend Modes which are specified in an Array of Names (issue 1…

…1279)

According to the specification, the first *supported* Blend Mode should be choosen in this case; please see https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/PDF32000_2008.pdf#G10.4848607

src/core/evaluator.js

@@ -125,8 +125,23 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
   };
 
   // Convert PDF blend mode names to HTML5 blend mode names.
-  function normalizeBlendMode(value) {
+  function normalizeBlendMode(value, parsingArray = false) {
+    if (Array.isArray(value)) {
+      // Use the first *supported* BM value in the Array (fixes issue11279.pdf).
+      for (let i = 0, ii = value.length; i < ii; i++) {
+        const maybeBM = normalizeBlendMode(value[i], /* parsingArray = */ true);
+        if (maybeBM) {
+          return maybeBM;
+        }
+      }
+      warn(`Unsupported blend mode Array: ${value}`);
+      return 'source-over';
+    }
+
     if (!isName(value)) {
+      if (parsingArray) {
+        return null;
+      }
       return 'source-over';
     }
     switch (value.name) {
@@ -164,7 +179,10 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
       case 'Luminosity':
         return 'luminosity';
     }
-    warn('Unsupported blend mode: ' + value.name);
+    if (parsingArray) {
+      return null;
+    }
+    warn(`Unsupported blend mode: ${value.name}`);
     return 'source-over';
   }
 

test/pdfs/.gitignore

@@ -85,6 +85,7 @@
 !issue11045.pdf
 !issue11150_reduced.pdf
 !issue11242_reduced.pdf
+!issue11279.pdf
 !bad-PageLabels.pdf
 !decodeACSuccessive.pdf
 !filled-background.pdf

test/test_manifest.json

@@ -1512,6 +1512,13 @@
        "link": false,
        "type": "eq"
     },
+    {  "id": "issue11279",
+       "file": "pdfs/issue11279.pdf",
+       "md5": "03361d24f3ed63b93f77abf731f8fc73",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "issue8480",
        "file": "pdfs/issue8480.pdf",
        "md5": "769bc07bf8041d95667f2d32aaf75665",