[PATCH] Work around a bad interaction between Tcl and cmd.exe with "^{tree}"

[Johannes Sixt <j.sixt@eudaptics.com>]

From: Johannes Sixt <johannes.sixt@telecom.at>

It seems that MSYS's wish does some quoting for Bourne shells, in
particular, escape the first '{' of the "^{tree}" suffix, but then it uses
cmd.exe to run the "git rev-parse" command. However, cmd.exe does not remove
the backslash, so that the resulting ref expression ends up in git's guts
as unrecognizable garbage.

Fortunately, recent versions of git can refer to the root tree object using
the notation "$commit:", which avoids the problematic case.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
---
 lib/commit.tcl |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/lib/commit.tcl b/lib/commit.tcl
index dc7c88c..43a5aca 100644
--- a/lib/commit.tcl
+++ b/lib/commit.tcl
@@ -258,7 +258,7 @@ proc commit_committree {fd_wt curHEAD msg} {
 	# -- Verify this wasn't an empty change.
 	#
 	if {$commit_type eq {normal}} {
-		set old_tree [git rev-parse "$PARENT^{tree}"]
+		set old_tree [git rev-parse "$PARENT:"]
 		if {$tree_id eq $old_tree} {
 			info_popup {No changes to commit.
 
-- 
1.5.3.rc0.32.g2968f