[glib: 1/4] gkeyfilesettingsbackend: Fix basename handling when group is unset

[Sebastian Dröge <sdroege src gnome org>]

commit 9d27c57f7035a6bb977070abadacfa479a0237d9
Author: Philip Withnall <pwithnall endlessos org>
Date:   Wed Feb 10 21:16:39 2021 +0000

    gkeyfilesettingsbackend: Fix basename handling when group is unset
    
    Fix an effective regression in commit
    7781a9cbd2fd0aa84bee0f4eee88470640ff6706, which happens when
    `convert_path()` is called with a `key` which contains no slashes. In
    that case, the `key` is entirely the `basename`.
    
    Prior to commit 7781a9cb, the code worked through a fluke of `i == -1`
    cancelling out with the various additions in the `g_memdup()` call, and
    effectively resulting in `g_strdup (key)`.
    
    Spotted by Guido Berhoerster.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 gio/gkeyfilesettingsbackend.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/gio/gkeyfilesettingsbackend.c b/gio/gkeyfilesettingsbackend.c
index 793eed02a..d57a9d421 100644
--- a/gio/gkeyfilesettingsbackend.c
+++ b/gio/gkeyfilesettingsbackend.c
@@ -188,7 +188,12 @@ convert_path (GKeyfileSettingsBackend  *kfsb,
     }
 
   if (basename)
-    *basename = g_memdup2 (last_slash + 1, key_len - (last_slash - key));
+    {
+      if (last_slash != NULL)
+        *basename = g_memdup2 (last_slash + 1, key_len - (last_slash - key));
+      else
+        *basename = g_strdup (key);
+    }
 
   return TRUE;
 }