Avoid cycles when getting operator list in patterns

src/core/evaluator.js

@@ -982,7 +982,8 @@ class PartialEvaluator {
     patternDict,
     operatorList,
     task,
-    localTilingPatternCache
+    localTilingPatternCache,
+    seenRefs
   ) {
     // Create an IR of the pattern code.
     const tilingOpList = new CheckedOperatorList();
@@ -998,6 +999,7 @@ class PartialEvaluator {
       task,
       resources: patternResources,
       operatorList: tilingOpList,
+      prevRefs: seenRefs,
     })
       .then(function () {
         const operatorListIR = tilingOpList.getIR();
@@ -1041,7 +1043,8 @@ class PartialEvaluator {
     task,
     state,
     fallbackFontDict = null,
-    cssFontInfo = null
+    cssFontInfo = null,
+    seenRefs = null
   ) {
     const fontName = fontArgs?.[0] instanceof Name ? fontArgs[0].name : null;
 
@@ -1051,7 +1054,8 @@ class PartialEvaluator {
       resources,
       task,
       fallbackFontDict,
-      cssFontInfo
+      cssFontInfo,
+      seenRefs
     );
 
     if (translated.font.isType3Font) {
@@ -1152,7 +1156,10 @@ class PartialEvaluator {
               value[0],
               operatorList,
               task,
-              stateManager.state
+              stateManager.state,
+              /* fallbackFontDict = */ null,
+              /* cssFontInfo = */ null,
+              seenRefs
             ).then(function (loadedName) {
               operatorList.addDependency(loadedName);
               gStateObj.push([key, [loadedName, value[1]]]);
@@ -1230,7 +1237,8 @@ class PartialEvaluator {
     resources,
     task,
     fallbackFontDict = null,
-    cssFontInfo = null
+    cssFontInfo = null,
+    seenRefs = null
   ) {
     const errorFont = async () =>
       new TranslatedFont({
@@ -1366,7 +1374,7 @@ class PartialEvaluator {
 
         if (translatedFont.isType3Font) {
           try {
-            await translated.loadType3Data(this, resources, task);
+            await translated.loadType3Data(this, resources, task, seenRefs);
           } catch (reason) {
             throw new Error(`Type3 font load error: ${reason}`);
           }
@@ -1577,7 +1585,8 @@ class PartialEvaluator {
     task,
     localColorSpaceCache,
     localTilingPatternCache,
-    localShadingPatternCache
+    localShadingPatternCache,
+    seenRefs
   ) {
     // compile tiling patterns
     const patternName = args.pop();
@@ -1619,7 +1628,8 @@ class PartialEvaluator {
             dict,
             operatorList,
             task,
-            localTilingPatternCache
+            localTilingPatternCache,
+            seenRefs
           );
         } else if (typeNum === PatternType.SHADING) {
           const shading = dict.get("Shading");
@@ -1934,7 +1944,9 @@ class PartialEvaluator {
                   operatorList,
                   task,
                   stateManager.state,
-                  fallbackFontDict
+                  fallbackFontDict,
+                  /* cssFontInfo = */ null,
+                  seenRefs
                 )
                 .then(function (loadedName) {
                   operatorList.addDependency(loadedName);
@@ -2112,7 +2124,8 @@ class PartialEvaluator {
                   task,
                   localColorSpaceCache,
                   localTilingPatternCache,
-                  localShadingPatternCache
+                  localShadingPatternCache,
+                  seenRefs
                 )
               );
               return;
@@ -2144,7 +2157,8 @@ class PartialEvaluator {
                   task,
                   localColorSpaceCache,
                   localTilingPatternCache,
-                  localShadingPatternCache
+                  localShadingPatternCache,
+                  seenRefs
                 )
               );
               return;
@@ -2731,7 +2745,10 @@ class PartialEvaluator {
         fontName,
         fontRef,
         resources,
-        task
+        task,
+        /* fallbackFontDict = */ null,
+        /* cssFontInfo = */ null,
+        seenRefs
       );
 
       textState.loadedName = translated.loadedName;
@@ -4893,7 +4910,7 @@ class TranslatedFont {
     );
   }
 
-  loadType3Data(evaluator, resources, task) {
+  loadType3Data(evaluator, resources, task, seenRefs = null) {
     if (this.#type3Loaded) {
       return this.#type3Loaded;
     }
@@ -4931,6 +4948,7 @@ class TranslatedFont {
             task,
             resources: fontResources,
             operatorList,
+            prevRefs: seenRefs,
           })
           .then(() => {
             // According to the PDF specification, section "9.6.5 Type 3 Fonts"

test/pdfs/.gitignore

@@ -912,3 +912,4 @@
 !smask_alpha_oob_transfer.pdf
 !smask_alpha_bc.pdf
 !smask_luminosity_oob_transfer.pdf
+!operator_list_cycle.pdf

test/pdfs/operator_list_cycle.pdf

@@ -0,0 +1,98 @@
+%PDF-1.7
+% ò¤ô
+1 0 obj <<
+  /Kids [3 0 R]
+  /Type /Pages
+  /Count 1
+>>
+endobj
+2 0 obj <<
+  /Type /Catalog
+  /Pages 1 0 R
+>>
+endobj
+3 0 obj <<
+  /Resources 11 0 R
+  /Type /Page
+  /Contents 10 0 R
+  /Parent 1 0 R
+>>
+endobj
+10 0 obj <<
+>>
+stream
+1 0 0 1 315.779 733.039 cm
+1 0 0 1 2.835 -173.614 cm
+1.04704 0 0 1.04704 0 0 cm
+/Im6 Do
+endstream
+endobj
+11 0 obj <<
+  /XObject <<
+    /Im6 12 0 R
+  >>
+>>
+endobj
+12 0 obj <<
+  /Subtype /Form
+  /Resources <<
+    /XObject <<
+      /x15 13 0 R
+    >>
+  >>
+>>
+stream
+/x15 Do
+endstream
+endobj
+13 0 obj <<
+  /Subtype /Form
+  /Resources <<
+    /Pattern <<
+      /p31 14 0 R
+    >>
+  >>
+>>
+stream
+q /Pattern cs /p31 scn /a0 gs
+0 0 224.720001 160.399994 re f
+Q
+endstream
+endobj
+14 0 obj <<
+  /PatternType 1
+  /BBox [0 0 225 161]
+  /Resources <<
+    /XObject <<
+      /x47 12 0 R
+    >>
+  >>
+>>
+stream
+/x47 Do
+endstream
+endobj
+xref
+0 15
+0000000000 65535 f 
+4294967295 00000 n 
+0000000078 00000 n 
+0000000131 00000 n 
+0000000000 65535 f 
+0000000000 65535 f 
+0000000000 65535 f 
+0000000000 65535 f 
+0000000000 65535 f 
+0000000000 65535 f 
+0000000221 00000 n 
+0000000348 00000 n 
+0000000405 00000 n 
+0000000531 00000 n 
+0000000712 00000 n 
+trailer <<
+  /Root 2 0 R
+  /Size 110
+>>
+startxref
+860
+%%EOF

test/unit/api_spec.js

@@ -4452,6 +4452,19 @@ have written that much by now. So, here’s to squashing bugs.`);
       }
     );
 
+    it("gets operator list, from a PDF with a Form -> Form -> Pattern -> Form cycle", async function () {
+      const loadingTask = getDocument(
+        buildGetDocumentParams("operator_list_cycle.pdf")
+      );
+      const pdfDoc = await loadingTask.promise;
+      const pdfPage = await pdfDoc.getPage(1);
+
+      const operatorList = await pdfPage.getOperatorList();
+      expect(operatorList.lastChunk).toEqual(true);
+
+      await loadingTask.destroy();
+    });
+
     it("gets operator list, containing Annotation-operatorLists", async function () {
       const loadingTask = getDocument(
         buildGetDocumentParams("annotation-line.pdf")