[gparted] Extract common code into Mount_Info::lookup_uuid_or_label() (#162)

[Curtis Gedak <gedakc src gnome org>]

commit f5e6239452961225203fbf89860137b086921c67
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Wed Aug 11 22:03:46 2021 +0100

    Extract common code into Mount_Info::lookup_uuid_or_label() (#162)
    
    Closes #162 - It is no longer possible to mount a LUKS encrypted file
                  system

 include/Mount_Info.h |  1 +
 src/Mount_Info.cc    | 54 +++++++++++++++++++---------------------------------
 2 files changed, 21 insertions(+), 34 deletions(-)
---
diff --git a/include/Mount_Info.h b/include/Mount_Info.h
index 7e8fee88..1e8a169c 100644
--- a/include/Mount_Info.h
+++ b/include/Mount_Info.h
@@ -67,6 +67,7 @@ private:
        static bool have_rootfs_dev( MountMapping & map );
        static void read_mountpoints_from_mount_command( MountMapping & map );
        static const MountEntry& find(MountMapping& map, const Glib::ustring& path);
+       static Glib::ustring lookup_uuid_or_label(const Glib::ustring& ref);
 };
 
 } //GParted
diff --git a/src/Mount_Info.cc b/src/Mount_Info.cc
index 5a81276e..1609b8bc 100644
--- a/src/Mount_Info.cc
+++ b/src/Mount_Info.cc
@@ -142,24 +142,11 @@ void Mount_Info::read_mountpoints_from_file( const Glib::ustring & filename, Mou
        struct mntent* p = NULL;
        while ( ( p = getmntent( fp ) ) != NULL )
        {
-               Glib::ustring node = p->mnt_fsname;
-               Glib::ustring mountpoint = p->mnt_dir;
+               Glib::ustring node = lookup_uuid_or_label(p->mnt_fsname);
+               if (node.empty())
+                       node = p->mnt_fsname;
 
-               Glib::ustring uuid = Utils::regexp_label( node, "^UUID=(.*)" );
-               if ( ! uuid.empty() )
-               {
-                       Glib::ustring temp = FS_Info::get_path_by_uuid(uuid);
-                       if (! temp.empty())
-                               node = temp;
-               }
-
-               Glib::ustring label = Utils::regexp_label( node, "^LABEL=(.*)" );
-               if ( ! label.empty() )
-               {
-                       Glib::ustring temp = FS_Info::get_path_by_label(label);
-                       if (! temp.empty())
-                               node = temp;
-               }
+               Glib::ustring mountpoint = p->mnt_dir;
 
                add_mountpoint_entry(map, node, mountpoint, parse_readonly_flag(p->mnt_opts));
        }
@@ -281,23 +268,7 @@ const MountEntry& Mount_Info::find(MountMapping& map, const Glib::ustring& path)
        }
        for (unsigned i = 0; i < ref_nodes.size(); i++)
        {
-               Glib::ustring node;
-               Glib::ustring uuid = Utils::regexp_label(ref_nodes[i].m_name, "^UUID=(.*)");
-               if (! uuid.empty())
-               {
-                       Glib::ustring temp = FS_Info::get_path_by_uuid(uuid);
-                       if (! temp.empty())
-                               node = temp;
-               }
-
-               Glib::ustring label = Utils::regexp_label(ref_nodes[i].m_name, "^LABEL=(.*)");
-               if (! label.empty())
-               {
-                       Glib::ustring temp = FS_Info::get_path_by_label(label);
-                       if (! temp.empty())
-                               node = temp;
-               }
-
+               Glib::ustring node = lookup_uuid_or_label(ref_nodes[i].m_name);
                if (! node.empty())
                {
                        // Insert new mount entry and delete the old one.
@@ -314,4 +285,19 @@ const MountEntry& Mount_Info::find(MountMapping& map, const Glib::ustring& path)
        return not_mounted;
 }
 
+
+// Return file system's block device given a UUID=... or LABEL=... reference, or return
+// the empty string when not found.
+Glib::ustring Mount_Info::lookup_uuid_or_label(const Glib::ustring& ref)
+{
+       if (ref.compare(0, 5, "UUID=") == 0)
+               return FS_Info::get_path_by_uuid(ref.substr(5));
+
+       if (ref.compare(0, 6, "LABEL=") == 0)
+               return FS_Info::get_path_by_label(ref.substr(6));
+
+       return "";
+}
+
+
 } //GParted