~/.local/share/tig/history may not be used since version 2.5.6

[yan12125]

Since 2.5.6 (d308b74, particularly), if $XDG_DATA_HOME is valid, tig runs mkdir(dirname(path), 0777);. However, dirname() may modify the string pointed to by path [1]. If that happens, path no longer points to the desired history file.

For example, on Arch LInux, dirname() changes path from

"/home/yen/.local/share/tig/history\0"

to

"/home/yen/.local/share/tig\0history\0"

The following open() fails as path is now a directory, and the fallback ~/.tig_history is used.

By the way, is it a good idea to use permission 0777?

[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirname.html

[yan12125]

Figured out a fix: #1217

[koutcher]

@yan12125 , thanks for reporting and fixing the issue. To my dismay, macOS version of dirname() does not behave the same as Linux version, so I missed that. 0777 is further restricted by the user's umask, I don't think we have a reason to be more restrictive.

[yan12125]

0777 is further restricted by the user's umask, I don't think we have a reason to be more restrictive.

Got it!