File rename handles zero-length substitutions incorrectly

[ply]

1. Problem

Suppose you want to replace a substring in some file names with another, so you do a File Rename operation with source pattern:

*OLDSTRING*

and target pattern:

\1NEWSTRING\2

If OLDSTRING occurs inside a filename, it is replaced correctly, but if at the beginning or end of the filename, the corresponding zero-length wildcard match is replaced by literal \1 or \2, respectively.

2. Expected

Wildcards that match a zero-length substring should be substituted with an empty string.

[boris]

The attached patch may fix the issue (according to GLib documentation, fnd_start and fnd_end will be both equal -1 for a zero-length match).

By the way, I wonder why mc uses its own numerous and complicated mc_search__regex_* functions instead of GLib's g_regex_replace etc.?

[andrew_b]

Replying to boris:

The attached patch may fix the issue

Thanks! I've modified your patch and added test.

Branch: 2952_zero_length_substitution.
Initial changeset:10ac6ec85c981f0051a1877fe5d29c06d644936b

By the way, I wonder why mc uses its own numerous and complicated mc_search__regex_* functions instead of GLib's g_regex_replace etc.?

It's hard to remember after several years.

[andrew_b]

Merged to master: [3fae7c227d5b5fd71d0f4470a15516314019aa41].

git log --pretty=oneline 774762a..3fae7c2