git-gui: Improve the Windows and Mac OS X shortcut creators

We now embed any GIT_* and SSH_* environment variables as well as
the path to the git wrapper executable into the Mac OS X .app file.
This should allow us to restore the environment properly when
we restart.

We also try to use proper Bourne shell single quoting when we can,
as this avoids any sort of problems that might occur due to a path
containing shell metacharacters.

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

git-gui.sh

@@ -475,6 +475,11 @@ proc git_write {args} {
 	return [open [concat $opt $cmdp $args] w]
 }
 
+proc sq {value} {
+	regsub -all ' $value "'\\''" value
+	return "'$value'"
+}
+
 proc load_current_branch {} {
 	global current_branch is_detached
 

lib/shortcut.tcl

@@ -13,10 +13,11 @@ proc do_windows_shortcut {} {
 			set fn ${fn}.bat
 		}
 		if {[catch {
+				set ge [file normalize [file dirname $::_git]]
 				set fd [open $fn w]
 				puts $fd "@ECHO Entering [reponame]"
 				puts $fd "@ECHO Starting git-gui... please wait..."
-				puts $fd "@SET PATH=[file normalize [gitexec]];%PATH%"
+				puts $fd "@SET PATH=$ge;%PATH%"
 				puts $fd "@SET GIT_DIR=[file normalize [gitdir]]"
 				puts -nonewline $fd "@\"[info nameofexecutable]\""
 				puts $fd " \"[file normalize $argv0]\""
@@ -62,17 +63,11 @@ proc do_cygwin_shortcut {} {
 					--unix \
 					--absolute \
 					[gitdir]]
-				set gw [exec cygpath \
-					--windows \
-					--absolute \
-					[file dirname [gitdir]]]
-				regsub -all ' $me "'\\''" me
-				regsub -all ' $gd "'\\''" gd
-				puts $fd "@ECHO Entering $gw"
+				puts $fd "@ECHO Entering [reponame]"
 				puts $fd "@ECHO Starting git-gui... please wait..."
 				puts -nonewline $fd "@\"$sh\" --login -c \""
-				puts -nonewline $fd "GIT_DIR='$gd'"
-				puts -nonewline $fd " '$me'"
+				puts -nonewline $fd "GIT_DIR=[sq [$gd]]"
+				puts -nonewline $fd " [sq $me]"
 				puts $fd "&\""
 				close $fd
 			} err]} {
@@ -90,6 +85,9 @@ proc do_macosx_app {} {
 		-initialdir [file join $env(HOME) Desktop] \
 		-initialfile "Git [reponame].app"]
 	if {$fn != {}} {
+		if {[file extension $fn] ne {.app}} {
+			set fn ${fn}.app
+		}
 		if {[catch {
 				set Contents [file join $fn Contents]
 				set MacOS [file join $Contents MacOS]
@@ -123,20 +121,27 @@ proc do_macosx_app {} {
 				close $fd
 
 				set fd [open $exe w]
-				set gd [file normalize [gitdir]]
-				set ep [file normalize [gitexec]]
-				regsub -all ' $gd "'\\''" gd
-				regsub -all ' $ep "'\\''" ep
 				puts $fd "#!/bin/sh"
-				foreach name [array names env] {
-					if {[string match GIT_* $name]} {
-						regsub -all ' $env($name) "'\\''" v
-						puts $fd "export $name='$v'"
+				foreach name [lsort [array names env]] {
+					set value $env($name)
+					switch -- $name {
+					GIT_DIR { set value [file normalize [gitdir]] }
+					}
+
+					switch -glob -- $name {
+					SSH_* -
+					GIT_* {
+						puts $fd "if test \"z\$$name\" = z; then"
+						puts $fd "  export $name=[sq $value]"
+						puts $fd "fi &&"
+					}
 					}
 				}
-				puts $fd "export PATH='$ep':\$PATH"
-				puts $fd "export GIT_DIR='$gd'"
-				puts $fd "exec [file normalize $argv0]"
+				puts $fd "export PATH=[sq [file dirname $::_git]]:\$PATH &&"
+				puts $fd "cd [sq [file normalize [pwd]]] &&"
+				puts $fd "exec \\"
+				puts $fd " [sq [info nameofexecutable]] \\"
+				puts $fd " [sq [file normalize $argv0]]"
 				close $fd
 
 				file attributes $exe -permissions u+x,g+x,o+x