Commit 6f4f2fb7 for libheif

commit 6f4f2fb71f4f6d39ef093603ff2ec1f8a25a45ca
Author: Dirk Farin <dirk.farin@gmail.com>
Date:   Fri Dec 26 13:39:09 2025 +0100

    regions: allow polyline with only 2 points

diff --git a/libheif/region.cc b/libheif/region.cc
index 7812ace2..092d060c 100644
--- a/libheif/region.cc
+++ b/libheif/region.cc
@@ -330,12 +330,23 @@ Error RegionGeometry_Polygon::parse(const std::vector<uint8_t>& data,
                  "Insufficient data remaining for polygon");
   }

-  if (numPoints < 3) {
-    return {
-      heif_error_Invalid_input,
-      heif_suberror_Unspecified,
-      "Region polygon with less than 3 points."
-    };
+  if (closed) {
+    if (numPoints < 3) {
+      return {
+        heif_error_Invalid_input,
+        heif_suberror_Unspecified,
+        "Region polygon with less than 3 points."
+      };
+    }
+  }
+  else {
+    if (numPoints < 2) {
+      return {
+        heif_error_Invalid_input,
+        heif_suberror_Unspecified,
+        "Region polyline with less than 2 points."
+      };
+    }
   }

   if (UINT32_MAX / numPoints < sizeof(Point)) {