Introduce RefRecursionChecker

6 files changed, 37 insertions, 35 deletions

diff --git a/poppler/Annot.cc b/poppler/Annot.cc
index aebcffcd..d62ba890 100644
--- a/poppler/Annot.cc
+++ b/poppler/Annot.cc
@@ -5314,19 +5314,8 @@ bool AnnotAppearanceBuilder::drawFormFieldChoice(const FormFieldChoice *fieldCho
     return true;
 }
 
-static bool insertIfNotAlreadyPresent(Ref r, std::set<int> *alreadySeenDicts)
-{
-    if (r == Ref::INVALID()) {
-        return true;
-    }
-
-    // std::pair<iterator,bool>
-    const auto insertResult = alreadySeenDicts->insert(r.num);
-    return insertResult.second;
-}
-
 // Should we also merge Arrays?
-static void recursiveMergeDicts(Dict *primary, const Dict *secondary, std::set<int> *alreadySeenDicts)
+static void recursiveMergeDicts(Dict *primary, const Dict *secondary, RefRecursionChecker *alreadySeenDicts)
 {
     for (int i = 0; i < secondary->getLength(); ++i) {
         const char *key = secondary->getKey(i);
@@ -5339,7 +5328,7 @@ static void recursiveMergeDicts(Dict *primary, const Dict *secondary, std::set<i
                 Ref secondaryRef;
                 Object secondaryObj = secondary->lookup(key, &secondaryRef);
                 if (secondaryObj.isDict()) {
-                    if (!insertIfNotAlreadyPresent(primaryRef, alreadySeenDicts) || !insertIfNotAlreadyPresent(secondaryRef, alreadySeenDicts)) {
+                    if (!alreadySeenDicts->insert(primaryRef) || !alreadySeenDicts->insert(secondaryRef)) {
                         // bad PDF
                         return;
                     }
@@ -5352,7 +5341,7 @@ static void recursiveMergeDicts(Dict *primary, const Dict *secondary, std::set<i
 
 static void recursiveMergeDicts(Dict *primary, const Dict *secondary)
 {
-    std::set<int> alreadySeenDicts;
+    RefRecursionChecker alreadySeenDicts;
     recursiveMergeDicts(primary, secondary, &alreadySeenDicts);
 }
 
diff --git a/poppler/FontInfo.cc b/poppler/FontInfo.cc
index 0be38923..551b98a1 100644
--- a/poppler/FontInfo.cc
+++ b/poppler/FontInfo.cc
@@ -134,21 +134,16 @@ void FontInfoScanner::scanFonts(XRef *xrefA, Dict *resDict, std::vector<FontInfo
             for (int i = 0; i < objDict.dictGetLength(); ++i) {
                 Ref obj2Ref;
                 const Object obj2 = objDict.getDict()->getVal(i, &obj2Ref);
-                if (obj2Ref != Ref::INVALID()) {
-                    // check for an already-seen object
-                    if (!visitedObjects.insert(obj2Ref.num).second) {
-                        continue;
-                    }
+                // check for an already-seen object
+                if (!visitedObjects.insert(obj2Ref)) {
+                    continue;
                 }
 
                 if (obj2.isStream()) {
                     Ref resourcesRef;
                     const Object resObj = obj2.streamGetDict()->lookup("Resources", &resourcesRef);
-
-                    if (resourcesRef != Ref::INVALID()) {
-                        if (!visitedObjects.insert(resourcesRef.num).second) {
-                            continue;
-                        }
+                    if (!visitedObjects.insert(resourcesRef)) {
+                        continue;
                     }
 
                     if (resObj.isDict() && resObj.getDict() != resDict) {
diff --git a/poppler/FontInfo.h b/poppler/FontInfo.h
index d13ae978..24903cdb 100644
--- a/poppler/FontInfo.h
+++ b/poppler/FontInfo.h
@@ -101,7 +101,7 @@ private:
     PDFDoc *doc;
     int currentPage;
     std::unordered_set<int> fonts;
-    std::unordered_set<int> visitedObjects;
+    RefRecursionChecker visitedObjects;
 
     void scanFonts(XRef *xrefA, Dict *resDict, std::vector<FontInfo *> *fontsList);
 };
diff --git a/poppler/Object.h b/poppler/Object.h
index d0975100..10fffc04 100644
--- a/poppler/Object.h
+++ b/poppler/Object.h
@@ -113,6 +113,28 @@ inline bool operator<(const Ref lhs, const Ref rhs) noexcept
     return lhs.gen < rhs.gen;
 }
 
+struct RefRecursionChecker
+{
+    RefRecursionChecker() { }
+
+    RefRecursionChecker(const RefRecursionChecker &) = delete;
+    RefRecursionChecker &operator=(const RefRecursionChecker &) = delete;
+
+    bool insert(Ref ref)
+    {
+        if (ref == Ref::INVALID()) {
+            return true;
+        }
+
+        // insert returns std::pair<iterator,bool>
+        // where the bool is whether the insert succeeded
+        return alreadySeenRefs.insert(ref.num).second;
+    }
+
+private:
+    std::set<int> alreadySeenRefs;
+};
+
 namespace std {
 
 template<>
diff --git a/poppler/PageLabelInfo.cc b/poppler/PageLabelInfo.cc
index 40a6e7fc..9b67b455 100644
--- a/poppler/PageLabelInfo.cc
+++ b/poppler/PageLabelInfo.cc
@@ -60,7 +60,7 @@ PageLabelInfo::Interval::Interval(Object *dict, int baseA)
 
 PageLabelInfo::PageLabelInfo(Object *tree, int numPages)
 {
-    std::set<int> alreadyParsedRefs;
+    RefRecursionChecker alreadyParsedRefs;
     parse(tree, alreadyParsedRefs);
 
     if (intervals.empty()) {
@@ -74,7 +74,7 @@ PageLabelInfo::PageLabelInfo(Object *tree, int numPages)
     curr->length = std::max(0, numPages - curr->base);
 }
 
-void PageLabelInfo::parse(const Object *tree, std::set<int> &alreadyParsedRefs)
+void PageLabelInfo::parse(const Object *tree, RefRecursionChecker &alreadyParsedRefs)
 {
     // leaf node
     Object nums = tree->dictLookup("Nums");
@@ -103,13 +103,9 @@ void PageLabelInfo::parse(const Object *tree, std::set<int> &alreadyParsedRefs)
         for (int i = 0; i < kidsArray->getLength(); ++i) {
             Ref ref;
             const Object kid = kidsArray->get(i, &ref);
-            if (ref != Ref::INVALID()) {
-                const int numObj = ref.num;
-                if (alreadyParsedRefs.find(numObj) != alreadyParsedRefs.end()) {
-                    error(errSyntaxError, -1, "loop in PageLabelInfo (numObj: {0:d})", numObj);
-                    continue;
-                }
-                alreadyParsedRefs.insert(numObj);
+            if (!alreadyParsedRefs.insert(ref)) {
+                error(errSyntaxError, -1, "loop in PageLabelInfo (ref.num: {0:d})", ref.num);
+                continue;
             }
             if (kid.isDict()) {
                 parse(&kid, alreadyParsedRefs);
diff --git a/poppler/PageLabelInfo.h b/poppler/PageLabelInfo.h
index bec70d32..2cfec29a 100644
--- a/poppler/PageLabelInfo.h
+++ b/poppler/PageLabelInfo.h
@@ -37,7 +37,7 @@ public:
     bool indexToLabel(int index, GooString *label) const;
 
 private:
-    void parse(const Object *tree, std::set<int> &parsedRefs);
+    void parse(const Object *tree, RefRecursionChecker &parsedRefs);
 
 private:
     struct Interval