git-gui: Don't require a .pvcsrc to create Tools/Migrate menu hack

The Tools/Migrate menu option is a hack just for me.  Yes, that's
right, git-gui has a hidden feature that really only works for me,
and the users that I support within my day-job's great firewall.
The menu option is not supported outside of that environment.

In the past we only enabled Tools/Migrate if our special local
script 'gui-miga' existed in the proper location, and if there
was a special '.pvcsrc' in the top level of the working directory.
This latter test for the '.pvcsrc' file is now failing, as the file
was removed from all Git repositories due to changes made to other
tooling within the great firewall's realm.

I have changed the test to only work on Cygwin, and only if the
special 'gui-miga' is present.  This works around the configuration
changes made recently within the great firewall's realm, but really
this entire Tools/Migrate thing should be abstracted out into some
sort of plugin system so other users can extend git-gui as they need.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Makefile

@@ -7,6 +7,8 @@ GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
 -include GIT-VERSION-FILE
 
+uname_O := $(shell sh -c 'uname -o 2>/dev/null || echo not')
+
 SCRIPT_SH = git-gui.sh
 GITGUI_BUILT_INS = git-citool
 ALL_PROGRAMS = $(GITGUI_BUILT_INS) $(patsubst %.sh,%,$(SCRIPT_SH))
@@ -58,11 +60,15 @@ exedir_SQ = $(subst ','\'',$(exedir))
 
 $(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
 	$(QUIET_GEN)rm -f $@ $@+ && \
+	GITGUI_RELATIVE= && \
 	if test '$(exedir_SQ)' = '$(libdir_SQ)'; then \
-		GITGUI_RELATIVE=1; \
+		if test "$(uname_O)" = Cygwin; \
+		then GITGUI_RELATIVE= ; \
+		else GITGUI_RELATIVE=1; \
+		fi; \
 	fi && \
 	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
-		-e 's|^exec wish "$$0"|exec $(subst |,'\|',$(TCLTK_PATH_SQ)) "$$0"|' \
+		-e 's|^ exec wish "$$0"| exec $(subst |,'\|',$(TCLTK_PATH_SQ)) "$$0"|' \
 		-e 's/@@GITGUI_VERSION@@/$(GITGUI_VERSION)/g' \
 		-e 's|@@GITGUI_RELATIVE@@|'$$GITGUI_RELATIVE'|' \
 		-e $$GITGUI_RELATIVE's|@@GITGUI_LIBDIR@@|$(libdir_SQ)|' \

git-gui.sh

@@ -1,6 +1,12 @@
 #!/bin/sh
 # Tcl ignores the next line -*- tcl -*- \
-exec wish "$0" -- "$@"
+ if test "z$*" = zversion \
+ || test "z$*" = z--version; \
+ then \
+	echo 'git-gui version @@GITGUI_VERSION@@'; \
+	exit; \
+ fi; \
+ exec wish "$0" -- "$@"
 
 set appvers {@@GITGUI_VERSION@@}
 set copyright {
@@ -271,11 +277,6 @@ proc tk_optionMenu {w varName args} {
 ##
 ## version check
 
-if {{--version} eq $argv || {version} eq $argv} {
-	puts "git-gui version $appvers"
-	exit
-}
-
 set req_maj 1
 set req_min 5
 
@@ -1544,8 +1545,7 @@ if {[is_MacOSX]} {
 
 	# -- Tools Menu
 	#
-	if {[file exists /usr/local/miga/lib/gui-miga]
+	if {[is_Cygwin] && [file exists /usr/local/miga/lib/gui-miga]} {
-		&& [file exists .pvcsrc]} {
 	proc do_miga {} {
 		global ui_status_value
 		if {![lock_index update]} return

lib/blame.tcl

@@ -272,6 +272,8 @@ constructor new {i_commit i_path} {
 			set cursorW %W
 			tk_popup $w.ctxm %X %Y
 		"
+		bind $i <Shift-Tab> "[list focus $w_cviewer];break"
+		bind $i <Tab>       "[list focus $w_cviewer];break"
 	}
 
 	foreach i [concat $w_columns $w_cviewer] {
@@ -287,8 +289,10 @@ constructor new {i_commit i_path} {
 		bind $i <Control-Key-f> {catch {%W yview scroll  1 pages};break}
 	}
 
+	bind $w_cviewer <Shift-Tab> "[list focus $w_file];break"
+	bind $w_cviewer <Tab>       "[list focus $w_file];break"
 	bind $w_cviewer <Button-1> [list focus $w_cviewer]
-	bind $top <Visibility> [list focus $top]
+	bind $w_file    <Visibility> [list focus $w_file]
 
 	grid configure $w.header -sticky ew
 	grid configure $w.file_pane -sticky nsew
@@ -483,7 +487,11 @@ method _read_file {fd jump} {
 } ifdeleted { catch {close $fd} }
 
 method _exec_blame {cur_w cur_d options cur_s} {
-	set cmd [list nice git blame]
+	set cmd [list]
+	if {![is_Windows] || [is_Cygwin]} {
+		lappend cmd nice
+	}
+	lappend cmd git blame
 	set cmd [concat $cmd $options]
 	lappend cmd --incremental
 	if {$commit eq {}} {