Re: [PATCH v2 03/10] mailmap: remove email copy and length limitation

Antoine Pelisse [off-list ref] writes:

quoted

+static struct string_list_item *lookup_prefix(struct string_list *map,
+                                             const char *string, size_t len)
+{
+       int i = string_list_find_insert_index(map, string, 1);
+       if (i < 0) {
+               /* exact match */
+               i = -1 - i;
+               /* does it match exactly? */
+               if (!map->items[i].string[len])
+                       return &map->items[i];

I'm not sure the condition above is necessary, as I don't see why an
exact match would not be an exact match.

You have a overlong string "ABCDEFG", but you only want to look for
"ABCDEF", i.e. len=6.  The string_list happens to have an existing
string "ABCDEFG".  The insert-index function will report an exact
match, but that does not mean you found what you are looking for. 

For the particular case of "looking up e-mail from a string-list
used for the mailmap, using a string that potentially has an extra
'>' at the end", it may not be an issue (i.e. your overlong string
would be "ABCDEF>", and the string-list used for the mailmap will
not have an entry that ends with '>'), but it is likely that people
will try to mimic this function or try to generalize and move it to
strbuf.c and at that point, such a special case condition will no
longer hold and the bug will manifest itself.  Being defensive like
the above is a way to avoid that.