git-gui: Change prior tree SHA-1 verification to use git_read

This cat-file was done on maint, where we did not have git_read
available to us.  But here on master we do, so we should make
use of it.

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

diff --git a/lib/commit.tcl b/lib/commit.tcl
index 3172d7c..46a78c1 100644 (file)
--- 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 fd_ot [open "| git cat-file commit $PARENT" r]
+               set fd_ot [git_read cat-file commit $PARENT]
                fconfigure $fd_ot -encoding binary -translation lf
                set old_tree [gets $fd_ot]
                close $fd_ot