Try to create the autosave directory if that does not exists

[Aurium]

I try to use the a sub-directory of my home as the Inkscape autosave location to don't mess with my files.

I only define the path "/home/aurium/ink-bak" and wait to see it works, but it can't create the directory automatically, and trow the warning to the terminal: "Cannot open autosave directory"

The automatic creation of the autosave directory is important to help the user in some ways:
  - fast deletion of autosaves deleting the dir without needing to re-create the dir.
  - protect misunderstanding when the user create a dir with a name and configure other name.
  - help user desktop migration, when only important things are bakuped, like specific configuration.
  - help the Inkscape configuration sharing.

When Inkscape really can't to create the dir, it must say "Cannot create the directory <dir path> for autosave"
(the <dir path> is really important to find personal errors)

[su_v (suv-lp)]

related reports:
Bug #570695 “show default|fallback autosave path”
Bug #635992 “autosave on by default”

[John Smith (john-smithi)]

Patch that attempts to create the autosave directory, if it doesn't exist.
Tested on Ubuntu 12.04 and Windows 7.

[su_v (suv-lp)]

> Patch that attempts to create the autosave directory, if it doesn't exist.

Is this correct?
- does not accept '~' or e.g. '$HOME'
- a relative path is resolved relative to '$HOME' (or is it to the directory Inkscape was launched from?)

Maybe the tooltip could contain minimal information about how what is accepted as input (Linux/OS X, Windows)?

[John Smith (john-smithi)]

Relative paths dont seem to work well - a single name "tmp1" works, but "tmp2/tmp3" doesnt seem to work on Ubuntu.
Relative paths are saved relative to the "current directory" [1] - usually the directory the application was launched from.
Variables such as '~', '$HOME' seem to be not "interpreted" to their absolute path equivalents and are used as-is in the function g_mkdir [2] (A wrapper for the POSIX mkdir() function)

How about the tooltip recommend saving absolute paths ?

[1] http://www.gtk.org/api/2.6/glib/glib-Miscellaneous-Utility-Functions.html#g-get-current-dir
[2] http://www.gtk.org/api/2.6/glib/glib-File-Utilities.html#g-mkdir

[John Smith (john-smithi)]

Committed as r11759.