Suppress unwanted messages from git-rebase.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

2 files changed, 17 insertions, 3 deletions

diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index f61185d..6168b19 100644
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -55,7 +55,8 @@ BEGIN {
 		      must_getcwd executable_on_path
                       waitstatusmsg failedcmd_waitstatus
 		      failedcmd_report_cmd failedcmd
-                      runcmd shell_cmd cmdoutput cmdoutput_errok
+                      runcmd runcmd_quieten
+		      shell_cmd cmdoutput cmdoutput_errok
 		      @git
                       git_rev_parse changedir_git_toplevel git_cat_file
 		      git_get_ref git_get_symref git_for_each_ref
@@ -397,6 +398,20 @@ sub shell_cmd {
     return qw(sh -ec), $first_shell.'; exec "$@"', 'x', @cmd;
 }
 
+# Runs the command in @_, but capturing its stdout and stderr.
+# Prints those to our stderr only if the command fails.
+sub runcmd_quieten {
+    debugcmd "+",@_;
+    $!=0; $?=-1;
+    my @real_cmd = shell_cmd <<'END', @_;
+                        set +e; output=$("$@" 2>&1); rc=$?; set -e
+                        if [ $rc = 0 ]; then exit 0; fi
+                        printf >&2 "%s\n" "$output"
+                        exit $rc
+END
+    failedcmd @_ if system @real_cmd;
+}
+
 sub cmdoutput_errok {
     confess Dumper(\@_)." ?" if grep { !defined } @_;
     local $printdebug_when_debuglevel = $debugcmd_when_debuglevel;
diff --git a/dgit b/dgit
index 8da13d3..f305f48 100755
--- a/dgit
+++ b/dgit
@@ -2794,8 +2794,7 @@ END
 		if ($use_absurd) {
 		    # Perhaps we should be using git-filter-branch,
 		    # but that's really considerably more awkward.
-		    # TODO: even --quiet still leave some stderr output ;-/
-		    runcmd
+		    runcmd_quieten
 		      @git, qw(rebase --keep-empty --allow-empty-message
 			       --onto unpa~1 unpa);
 		}