t7800-difftool.sh: Simplify the --extcmd test

Instead of running 'grep', 'echo', and 'wc' we simply compare
git-difftool's output against a known good value.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 8ee186a5fbda8b52cf3dd817a76f2f560505a253..1d9e07b0d84347be4a6bbd5d8b766f20fede1786 100755 (executable)
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -15,6 +15,9 @@ if ! test_have_prereq PERL; then
        test_done
 fi
 
+LF='
+'
+
 remove_config_vars()
 {
        # Unset all config variables used by git-difftool
@@ -219,19 +222,13 @@ test_expect_success 'difftool.<tool>.path' '
        restore_test_defaults
 '
 
-test_expect_success 'difftool --extcmd=...' '
+test_expect_success 'difftool --extcmd=cat' '
        diff=$(git difftool --no-prompt --extcmd=cat branch) &&
+       test "$diff" = branch"$LF"master
 
-       lines=$(echo "$diff" | wc -l) &&
-       test "$lines" -eq 2 &&
 
-       lines=$(echo "$diff" | grep master | wc -l) &&
-       test "$lines" -eq 1 &&
 
-       lines=$(echo "$diff" | grep branch | wc -l) &&
-       test "$lines" -eq 1 &&
 
-       restore_test_defaults
 '
 
 test_done