Filter out repeated forms

Some files like the one from KDE bug 426467 has the same signature
repeated 23 times in the Fields field, just return it one

1 files changed, 6 insertions, 0 deletions

diff --git a/poppler/Form.cc b/poppler/Form.cc
index b7ffc196..2ea343dd 100644
--- a/poppler/Form.cc
+++ b/poppler/Form.cc
@@ -2005,6 +2005,7 @@ Form::Form(PDFDoc *docA, Object *acroFormA)
     obj1 = acroForm->dictLookup("Fields");
     if (obj1.isArray()) {
         Array *array = obj1.getArray();
+        std::set<Ref> alreadyReadRefs;
         for (int i = 0; i < array->getLength(); i++) {
             Object obj2 = array->get(i);
             const Object &oref = array->getNF(i);
@@ -2018,6 +2019,11 @@ Form::Form(PDFDoc *docA, Object *acroFormA)
                 continue;
             }
 
+            if (alreadyReadRefs.find(oref.getRef()) != alreadyReadRefs.end()) {
+                continue;
+            }
+            alreadyReadRefs.insert(oref.getRef());
+
             if (numFields >= size) {
                 size += 16;
                 rootFields = (FormField **)greallocn(rootFields, size, sizeof(FormField *));