base64Decode: clearer error message when an invalid character is dete…

…cted Output the offending string in its entirety to provide context. Closes NixOS#8479
brianmcgee · Jul 31, 2023 · dc217c8 · dc217c8
1 parent dcdd5fe
commit dc217c8
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
@@ -1618,8 +1618,9 @@ std::string base64Decode(std::string_view s)
         if (c == '\n') continue;
 
         char digit = base64DecodeChars[(unsigned char) c];
-        if (digit == npos)
-            throw Error("invalid character in Base64 string: '%c'", c);
+        if (digit == npos) {
+            throw Error("invalid character in Base64 string: '%c' in %s", c, s.data());
+        }
 
         bits += 6;
         d = d << 6 | digit;