Add bounds check of resourceSize. (#856)

tests/bugfixes/github/test_issue_855.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+
+from system_tests import CaseMeta, path
+
+
+class OutOfMemoryInPsdImageReadMetadata(metaclass=CaseMeta):
+    """
+    Regression test for the bug described in:
+    https://github.com/Exiv2/exiv2/issues/855
+
+    There is no bounds check on the value of resourceSize,
+    leading to an out-of-memory error.
+    """
+    url = "https://github.com/Exiv2/exiv2/issues/855"
+
+    filename = path("$data_path/issue_855_poc.psd")
+    commands = ["$exiv2 $filename"]
+    stdout = [""]
+    stderr = ["""Warning: Failed to decode IPTC metadata.
+Exiv2 exception in print action for file $filename:
+corrupted image metadata
+"""
+]
+    retval = [1]