From 2f7c9a7f310dae23989b4acd49514abc58334e5b Mon Sep 17 00:00:00 2001
From: "Shawn O. Pearce" <spearce@spearce.org>
Date: Thu, 20 Sep 2007 21:25:34 -0400
Subject: [PATCH] git-gui: Support native Win32 Tcl/Tk under Cygwin

Cygwin has been stuck on the 8.4.1 version of Tcl/Tk for quite some
time, even though the main Tcl/Tk distribution is already shipping
an 8.4.15.  The problem is Tcl/Tk no longer supports Cygwin so
apparently building the package for Cygwin is now a non-trivial task.

Its actually quite easy to build the native Win32 version of Tcl/Tk
by compiling with the -mno-cygwin flag passed to GCC but this means
we lose all of the "fancy" Cygwin path translations that the Tcl
library was doing for us.  This is particularly an issue when we
are trying to start git-gui through the git wrapper as the git
wrapper is passing off a Cygwin path for $0 and Tcl cannot find
the startup script or the library directory.

We now use `cygpath -m -a` to convert the UNIX style paths to Windows
style paths in our startup script if we are building on Cygwin.
Doing so allows either the Cygwin-ized Tcl/Tk 8.4.1 that comes with
Cygwin or a manually built 8.4.15 that is running the pure Win32
implementation to read our script.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Makefile   | 32 ++++++++++++++++++++------------
 git-gui.sh |  5 +++--
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/Makefile b/Makefile
index 8c87d836d8..6236dd6ad3 100644
--- a/Makefile
+++ b/Makefile
@@ -92,27 +92,35 @@ gitexecdir_SQ = $(subst ','\'',$(gitexecdir))
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 TCL_PATH_SQ = $(subst ','\'',$(TCL_PATH))
 TCLTK_PATH_SQ = $(subst ','\'',$(TCLTK_PATH))
+TCLTK_PATH_SED = $(subst ','\'',$(subst \,\\,$(TCLTK_PATH)))
 
 gg_libdir ?= $(sharedir)/git-gui/lib
 libdir_SQ  = $(subst ','\'',$(gg_libdir))
+libdir_SED = $(subst ','\'',$(subst \,\\,$(gg_libdir)))
+exedir     = $(dir $(gitexecdir))share/git-gui/lib
 
-exedir    = $(dir $(gitexecdir))share/git-gui/lib
-exedir_SQ = $(subst ','\'',$(exedir))
+GITGUI_SCRIPT   := $$0
+GITGUI_RELATIVE :=
+
+ifeq ($(exedir),$(gg_libdir))
+	GITGUI_RELATIVE := 1
+endif
+
+ifeq ($(uname_O),Cygwin)
+	GITGUI_SCRIPT := `cygpath --windows --absolute "$(GITGUI_SCRIPT)"`
+	ifeq ($(GITGUI_RELATIVE),)
+		gg_libdir := $(shell cygpath --windows --absolute "$(gg_libdir)")
+	endif
+endif
 
 $(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
 	$(QUIET_GEN)rm -f $@ $@+ && \
-	GITGUI_RELATIVE= && \
-	if test '$(exedir_SQ)' = '$(libdir_SQ)'; then \
-		if test "$(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 '1,30s|^ argv0=$$0| argv0=$(GITGUI_SCRIPT)|' \
+		-e '1,30s|^ exec wish | exec '\''$(TCLTK_PATH_SED)'\'' |' \
 		-e 's/@@GITGUI_VERSION@@/$(GITGUI_VERSION)/g' \
-		-e 's|@@GITGUI_RELATIVE@@|'$$GITGUI_RELATIVE'|' \
-		-e $$GITGUI_RELATIVE's|@@GITGUI_LIBDIR@@|$(libdir_SQ)|' \
+		-e 's|@@GITGUI_RELATIVE@@|$(GITGUI_RELATIVE)|' \
+		-e '$(GITGUI_RELATIVE)s|@@GITGUI_LIBDIR@@|$(libdir_SED)|' \
 		$@.sh >$@+ && \
 	chmod +x $@+ && \
 	mv $@+ $@
diff --git a/git-gui.sh b/git-gui.sh
index db1507cdec..5a465e1c7d 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -6,7 +6,8 @@
 	echo 'git-gui version @@GITGUI_VERSION@@'; \
 	exit; \
  fi; \
- exec wish "$0" -- "$@"
+ argv0=$0; \
+ exec wish "$argv0" -- "$@"
 
 set appvers {@@GITGUI_VERSION@@}
 set copyright {
@@ -740,7 +741,7 @@ if {[catch {
 	exit 1
 }
 if {![file isdirectory $_gitdir] && [is_Cygwin]} {
-	catch {set _gitdir [exec cygpath --unix $_gitdir]}
+	catch {set _gitdir [exec cygpath --windows $_gitdir]}
 }
 if {![file isdirectory $_gitdir]} {
 	catch {wm withdraw .}