Merge git://repo.or.cz/git-gui into pt/git-gui

* git://repo.or.cz/git-gui:
  git-gui: fix size and position of window panes on startup
  git-gui: mc cannot be used before msgcat has been loaded
  git-gui: use textconv filter for diff and blame
  git-gui: Avoid using the <<Copy>> binding as a menu accelerator on win32
  git-gui: fix shortcut creation on cygwin
  git-gui: fix PATH environment for mingw development environment
  git-gui: fix usage of _gitworktree when creating shortcut for windows
  git-gui: fix "Explore Working Copy" for Windows again
  git-gui: fix usage of themed widgets variable
  git-gui: Handle failure of core.worktree to identify the working directory.
  git-gui: check whether systems nice command works or disable it

git-gui/lib/diff.tcl

@@ -55,7 +55,7 @@ proc handle_empty_diff {} {
 
 	set path $current_diff_path
 	set s $file_states($path)
-	if {[lindex $s 0] ne {_M}} return
+	if {[lindex $s 0] ne {_M} || [has_textconv $path]} return
 
 	# Prevent infinite rescan loops
 	incr diff_empty_count
@@ -280,6 +280,9 @@ proc start_show_diff {cont_info {add_opts {}}} {
 			lappend cmd diff-files
 		}
 	}
+	if {![is_config_false gui.textconv] && [git-version >= 1.6.1]} {
+		lappend cmd --textconv
+	}
 
 	if {[string match {160000 *} [lindex $s 2]]
 	 || [string match {160000 *} [lindex $s 3]]} {