[gimp] app: add contents of /.flatpak-info in the verbose info.

[Jehan <jehanp src gnome org>]

commit bc5f6371e9ac441caf6844c157cf4dda62a9fbbb
Author: Jehan <jehan girinstud io>
Date:   Mon Jul 13 15:06:54 2020 +0200

    app: add contents of /.flatpak-info in the verbose info.
    
    This file is available in a flatpak sandbox and will contain various
    info such as the build commit, very useful info as we can have several
    builds for a same version. For instance if we have exactly the right
    commit, we can load exactly the same binary as a bug reporter very
    easily, hence are able to get source correspondance without necessarily
    asking reporters to install debug symbols (though it stays easier if
    they can do it).
    
    Other interesting info contained in this file are the exact runtime
    used, the installed application or runtime extensions, the permissions
    (people may override our flatpak permissions so it's useful to be able
    to check when they did) and environment variables…

 app/gimp-version.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
---
diff --git a/app/gimp-version.c b/app/gimp-version.c
index 3d1894a036..6e311c8252 100644
--- a/app/gimp-version.c
+++ b/app/gimp-version.c
@@ -220,6 +220,7 @@ gimp_version (gboolean be_verbose,
     {
       gchar *verbose_info;
       gchar *lib_versions;
+      gchar *flatpak_info = NULL;
 
       lib_versions = gimp_library_versions (localized);
       verbose_info = g_strdup_printf ("git-describe: %s\n"
@@ -234,9 +235,22 @@ gimp_version (gboolean be_verbose,
                                       lib_versions);
       g_free (lib_versions);
 
-      temp = g_strconcat (version, verbose_info, NULL);
+      /* This file should be available at root path in a flatpak
+       * environment. Just add its contents to the verbose output if it
+       * exists. Silently ignore otherwise.
+       */
+      if (g_file_get_contents ("/.flatpak-info", &flatpak_info, NULL, NULL))
+        {
+          temp = g_strdup_printf ("\n# Flatpak info #\n%s",
+                                  flatpak_info);
+          g_free (flatpak_info);
+          flatpak_info = temp;
+        }
+      temp = g_strconcat (version, verbose_info, flatpak_info, NULL);
       g_free (version);
       g_free (verbose_info);
+      g_free (flatpak_info);
+
       version = temp;
     }