Fix assertion failure in crwimage_int.cpp (backport #1739)

src/crwimage_int.cpp

@@ -1228,13 +1228,17 @@ namespace Exiv2 {
         std::memset(buf.pData_, 0x0, buf.size_);
 
         uint16_t len = 0;
+
         for (auto&& exif : exifData) {
             if (exif.ifdId() != ifdId)
                 continue;
             const uint16_t s = exif.tag() * 2 + static_cast<uint16_t>(exif.size());
-            assert(s <= size);
-            if (len < s) len = s;
-            exif.copy(buf.pData_ + exif.tag() * 2, byteOrder);
+            if (s <= size) {
+                if (len < s) len = s;
+                exif.copy(buf.pData_ + exif.tag() * 2, byteOrder);
+            } else {
+                EXV_ERROR << "packIfdId out-of-bounds error: s = " << std::dec << s << "\n";
+            }
         }
         // Round the size to make it even.
         buf.size_ = len + len%2;

tests/bugfixes/github/test_issue_ghsa_mv9g_fxh2_m49m.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+from system_tests import CaseMeta, path
+
+class test_issue_ghsa_mv9g_fxh2_m49m(metaclass=CaseMeta):
+
+    filename = path("$data_path/test_issue_ghsa_mv9g_fxh2_m49m.crw")
+    commands  = ["$exiv2 -q fi $filename"]
+    stdout = [""]
+    stderr = ["""Exiv2 exception in fixiso action for file $filename:
+$kerCorruptedMetadata
+"""]
+    retval = [1]