3 files changed, 58 insertions, 7 deletions

diff --git a/source/pdf/pdf-object.c b/source/pdf/pdf-object.c
index b4e33f3c..1c19ba4f 100644
--- a/source/pdf/pdf-object.c
+++ b/source/pdf/pdf-object.c
@@ -1265,11 +1265,14 @@ pdf_dict_geta(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *abbrev)
 	return pdf_dict_get(ctx, obj, abbrev);
 }
 
-void
-pdf_dict_put(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val)
+static void
+pdf_dict_get_put(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val, pdf_obj **old_val)
 {
 	int i;
 
+	if (old_val)
+		*old_val = NULL;
+
 	RESOLVE(obj);
 	if (!OBJ_IS_DICT(obj))
 		fz_throw(ctx, FZ_ERROR_GENERIC, "not a dict (%s)", pdf_objkindstr(obj));
@@ -1295,7 +1298,10 @@ pdf_dict_put(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val)
 		{
 			pdf_obj *d = DICT(obj)->items[i].v;
 			DICT(obj)->items[i].v = pdf_keep_obj(ctx, val);
-			pdf_drop_obj(ctx, d);
+			if (old_val)
+				*old_val = d;
+			else
+				pdf_drop_obj(ctx, d);
 		}
 	}
 	else
@@ -1316,10 +1322,27 @@ pdf_dict_put(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val)
 }
 
 void
+pdf_dict_put(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val)
+{
+	pdf_dict_get_put(ctx, obj, key, val, NULL);
+}
+
+void
 pdf_dict_put_drop(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val)
 {
 	fz_try(ctx)
-		pdf_dict_put(ctx, obj, key, val);
+		pdf_dict_get_put(ctx, obj, key, val, NULL);
+	fz_always(ctx)
+		pdf_drop_obj(ctx, val);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
+}
+
+void
+pdf_dict_get_put_drop(fz_context *ctx, pdf_obj *obj, pdf_obj *key, pdf_obj *val, pdf_obj **old_val)
+{
+	fz_try(ctx)
+		pdf_dict_get_put(ctx, obj, key, val, old_val);
 	fz_always(ctx)
 		pdf_drop_obj(ctx, val);
 	fz_catch(ctx)
diff --git a/source/pdf/pdf-repair.c b/source/pdf/pdf-repair.c
index 690bf15a..167f6097 100644
--- a/source/pdf/pdf-repair.c
+++ b/source/pdf/pdf-repair.c
@@ -260,6 +260,27 @@ pdf_repair_obj_stm(fz_context *ctx, pdf_document *doc, int stm_num)
 	}
 }
 
+static void
+orphan_object(fz_context *ctx, pdf_document *doc, pdf_obj *obj)
+{
+	if (doc->orphans_count == doc->orphans_max)
+	{
+		int new_max = (doc->orphans_max ? doc->orphans_max*2 : 32);
+
+		fz_try(ctx)
+		{
+			doc->orphans = fz_resize_array(ctx, doc->orphans, new_max, sizeof(*doc->orphans));
+			doc->orphans_max = new_max;
+		}
+		fz_catch(ctx)
+		{
+			pdf_drop_obj(ctx, obj);
+			fz_rethrow(ctx);
+		}
+	}
+	doc->orphans[doc->orphans_count++] = obj;
+}
+
 void
 pdf_repair_xref(fz_context *ctx, pdf_document *doc)
 {
@@ -528,12 +549,13 @@ pdf_repair_xref(fz_context *ctx, pdf_document *doc)
 			/* correct stream length for unencrypted documents */
 			if (!encrypt && list[i].stm_len >= 0)
 			{
+				pdf_obj *old_obj = NULL;
 				dict = pdf_load_object(ctx, doc, list[i].num);
 
 				length = pdf_new_int(ctx, doc, list[i].stm_len);
-				pdf_dict_put(ctx, dict, PDF_NAME_Length, length);
-				pdf_drop_obj(ctx, length);
-
+				pdf_dict_get_put_drop(ctx, dict, PDF_NAME_Length, length, &old_obj);
+				if (old_obj)
+					orphan_object(ctx, doc, old_obj);
 				pdf_drop_obj(ctx, dict);
 			}
 		}
diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c
index 7d21775a..0cf20d4c 100644
--- a/source/pdf/pdf-xref.c
+++ b/source/pdf/pdf-xref.c
@@ -1620,6 +1620,12 @@ pdf_drop_document_imp(fz_context *ctx, pdf_document *doc)
 
 		pdf_drop_resource_tables(ctx, doc);
 
+		for (i = 0; i < doc->orphans_count; i++)
+		{
+			pdf_drop_obj(ctx, doc->orphans[i]);
+		}
+		fz_free(ctx, doc->orphans);
+
 		fz_free(ctx, doc);
 	}
 	fz_always(ctx)