Merge branch 'th/git-diffall'

* th/git-diffall:
  contrib/diffall: fix cleanup trap on Windows
  contrib/diffall: eliminate duplicate while loops
  contrib/diffall: eliminate use of tar
  contrib/diffall: create tmp dirs without mktemp
  contrib/diffall: comment actual reason for 'cdup'

contrib/diffall/git-diffall

@@ -36,21 +36,20 @@ fi
 
 start_dir=$(pwd)
 
-# needed to access tar utility
+# All the file paths returned by the diff command are relative to the root
+# of the working copy. So if the script is called from a subdirectory, it
+# must switch to the root of working copy before trying to use those paths.
 cdup=$(git rev-parse --show-cdup) &&
 cd "$cdup" || {
 	echo >&2 "Cannot chdir to $cdup, the toplevel of the working tree"
 	exit 1
 }
 
-# mktemp is not available on all platforms (missing from msysgit)
-# Use a hard-coded tmp dir if it is not available
-tmp="$(mktemp -d -t tmp.XXXXXX 2>/dev/null)" || {
-	tmp=/tmp/git-diffall-tmp.$$
-	mkdir "$tmp" || exit 1
-}
-
-trap 'rm -rf "$tmp" 2>/dev/null' EXIT
+# set up temp dir
+tmp=$(perl -e 'use File::Temp qw(tempdir);
+	$t=tempdir("/tmp/git-diffall.XXXXX") or exit(1);
+	print $t') || exit 1
+trap 'rm -rf "$tmp"' EXIT
 
 left=
 right=
@@ -180,34 +179,32 @@ fi
 mkdir -p "$tmp/$left_dir" "$tmp/$right_dir"
 
 # Populate the tmp/right_dir directory with the files to be compared
-if test -n "$right"
-then
-	while read name
-	do
+while read name
+do
+	if test -n "$right"
+	then
 		ls_list=$(git ls-tree $right "$name")
 		if test -n "$ls_list"
 		then
 			mkdir -p "$tmp/$right_dir/$(dirname "$name")"
 			git show "$right":"$name" >"$tmp/$right_dir/$name" || true
 		fi
-	done < "$tmp/filelist"
-elif test -n "$compare_staged"
-then
-	while read name
-	do
+	elif test -n "$compare_staged"
+	then
 		ls_list=$(git ls-files -- "$name")
 		if test -n "$ls_list"
 		then
 			mkdir -p "$tmp/$right_dir/$(dirname "$name")"
 			git show :"$name" >"$tmp/$right_dir/$name"
 		fi
-	done < "$tmp/filelist"
-else
-	# Mac users have gnutar rather than tar
-	(tar --ignore-failed-read -c -T "$tmp/filelist" | (cd "$tmp/$right_dir" && tar -x)) || {
-		gnutar --ignore-failed-read -c -T "$tmp/filelist" | (cd "$tmp/$right_dir" && gnutar -x)
-	}
-fi
+	else
+		if test -e "$name"
+		then
+			mkdir -p "$tmp/$right_dir/$(dirname "$name")"
+			cp "$name" "$tmp/$right_dir/$name"
+		fi
+	fi
+done < "$tmp/filelist"
 
 # Populate the tmp/left_dir directory with the files to be compared
 while read name
@@ -236,9 +233,8 @@ do
 	fi
 done < "$tmp/filelist"
 
-cd "$tmp"
-LOCAL="$left_dir"
-REMOTE="$right_dir"
+LOCAL="$tmp/$left_dir"
+REMOTE="$tmp/$right_dir"
 
 if test -n "$diff_tool"
 then