[gparted] Resolve UUID= and LABEL= refs when searching Mount_Info (#162)

[Curtis Gedak <gedakc src gnome org>]

commit 49747f656d40951d3cf81afb6a3d1fe5e0915226
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Tue Aug 10 21:08:06 2021 +0100

    Resolve UUID= and LABEL= refs when searching Mount_Info (#162)
    
    Implemented the second half of the solution described in the previous
    commit.  Resolve UUID= and LABEL= references when searching in the
    Mount_Info cache so that mount points of encrypted file systems listed
    in /etc/fstab can be found using the later added FS_Info details.
    
    Closes #162 - It is no longer possible to mount a LUKS encrypted file
                  system

 include/Mount_Info.h |  2 +-
 src/Mount_Info.cc    | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 3 deletions(-)
---
diff --git a/include/Mount_Info.h b/include/Mount_Info.h
index a498e835..7e8fee88 100644
--- a/include/Mount_Info.h
+++ b/include/Mount_Info.h
@@ -66,7 +66,7 @@ private:
                                                      MountMapping & map );
        static bool have_rootfs_dev( MountMapping & map );
        static void read_mountpoints_from_mount_command( MountMapping & map );
-       static const MountEntry & find( const MountMapping & map, const Glib::ustring & path );
+       static const MountEntry& find(MountMapping& map, const Glib::ustring& path);
 };
 
 } //GParted
diff --git a/src/Mount_Info.cc b/src/Mount_Info.cc
index fdf1141f..5a81276e 100644
--- a/src/Mount_Info.cc
+++ b/src/Mount_Info.cc
@@ -254,12 +254,62 @@ void Mount_Info::read_mountpoints_from_mount_command( MountMapping & map )
        }
 }
 
-const MountEntry & Mount_Info::find( const MountMapping & map, const Glib::ustring & path )
+
+const MountEntry& Mount_Info::find(MountMapping& map, const Glib::ustring& path)
 {
-       MountMapping::const_iterator iter_mp = map.find( BlockSpecial( path ) );
+       BlockSpecial bs_path = BlockSpecial(path);
+
+       // 1) Key look up by path.  E.g. BlockSpecial("/dev/sda1").
+       MountMapping::const_iterator iter_mp = map.find(bs_path);
        if ( iter_mp != map.end() )
                return iter_mp->second;
 
+       // 2) Not found so iterate over all mount entries resolving UUID= and LABEL=
+       //    references; checking after each for the requested mount entry.
+       //    (Unresolved UUID= and LABEL= references are added by
+       //    read_mountpoints_from_file("/etc/fstab", fstab_info) for open encryption
+       //    mappings as the file system details are only added later into the FS_Info
+       //    cache by GParted_Core::detect_filesystem_in_encryption_mappings()).
+       std::vector<BlockSpecial> ref_nodes;
+       for (iter_mp = map.begin(); iter_mp != map.end(); ++iter_mp)
+       {
+               if (iter_mp->first.m_name.compare(0, 5, "UUID=")  == 0 ||
+                   iter_mp->first.m_name.compare(0, 6, "LABEL=") == 0   )
+               {
+                       ref_nodes.push_back(iter_mp->first);
+               }
+       }
+       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;
+               }
+
+               if (! node.empty())
+               {
+                       // Insert new mount entry and delete the old one.
+                       map[BlockSpecial(node)] = map[ref_nodes[i]];
+                       map.erase(ref_nodes[i]);
+
+                       if (BlockSpecial(node) == bs_path)
+                               // This resolved mount entry is the one being searched for.
+                               return map[bs_path];
+               }
+       }
+
        static MountEntry not_mounted = MountEntry();
        return not_mounted;
 }