Merge pull request #1918 from rabauke/my_fix_01

fix out of range access, minor performance improvement

src/tags_int.cpp

@@ -3265,8 +3265,8 @@ namespace Exiv2 {
         }
 
         std::string stringValue = value.toString();
-        if (stringValue.at(19) == 'Z') {
-            stringValue = stringValue.substr(0, 19);
+        if (stringValue.size() == 20 && stringValue.at(19) == 'Z') {
+            stringValue.pop_back();
         }
         std::replace(stringValue.begin(), stringValue.end(), 'T', ' ');
         std::replace(stringValue.begin(), stringValue.end(), '-', ':');

tests/bugfixes/github/test_issue_1918.py

@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+
+from system_tests import CaseMeta, path, check_no_ASAN_UBSAN_errors
+
+class PrintXmpDateOutOfBoundsIndex19(metaclass=CaseMeta):
+    """
+    Regression test for the bug described in:
+    https://github.com/Exiv2/exiv2/issues/1918
+    """
+    url = "https://github.com/Exiv2/exiv2/issues/1918"
+
+    filename = path("$data_path/issue_1918_poc.jpg")
+    commands = ["$exiv2 -px $filename"]
+    stderr = [""]
+    retval = [0]
+
+    compare_stdout = check_no_ASAN_UBSAN_errors