Merge branch 'sg/test-i18ngrep'

Test fixes.

* sg/test-i18ngrep:
  t: make 'test_i18ngrep' more informative on failure
  t: validate 'test_i18ngrep's parameters
  t: move 'test_i18ncmp' and 'test_i18ngrep' to 'test-lib-functions.sh'
  t5536: let 'test_i18ngrep' read the file without redirection
  t5510: consolidate 'grep' and 'test_i18ngrep' patterns
  t4001: don't run 'git status' upstream of a pipe
  t6022: don't run 'git merge' upstream of a pipe
  t5812: add 'test_i18ngrep's missing filename parameter
  t5541: add 'test_i18ngrep's missing filename parameter

t/test-lib-functions.sh

@@ -705,6 +705,60 @@ test_cmp_bin() {
 	cmp "$@"
 }
 
+# Use this instead of test_cmp to compare files that contain expected and
+# actual output from git commands that can be translated.  When running
+# under GETTEXT_POISON this pretends that the command produced expected
+# results.
+test_i18ncmp () {
+	test -n "$GETTEXT_POISON" || test_cmp "$@"
+}
+
+# Use this instead of "grep expected-string actual" to see if the
+# output from a git command that can be translated either contains an
+# expected string, or does not contain an unwanted one.  When running
+# under GETTEXT_POISON this pretends that the command produced expected
+# results.
+test_i18ngrep () {
+	eval "last_arg=\${$#}"
+
+	test -f "$last_arg" ||
+	error "bug in the test script: test_i18ngrep requires a file" \
+	      "to read as the last parameter"
+
+	if test $# -lt 2 ||
+	   { test "x!" = "x$1" && test $# -lt 3 ; }
+	then
+		error "bug in the test script: too few parameters to test_i18ngrep"
+	fi
+
+	if test -n "$GETTEXT_POISON"
+	then
+		# pretend success
+		return 0
+	fi
+
+	if test "x!" = "x$1"
+	then
+		shift
+		! grep "$@" && return 0
+
+		echo >&2 "error: '! grep $@' did find a match in:"
+	else
+		grep "$@" && return 0
+
+		echo >&2 "error: 'grep $@' didn't find a match in:"
+	fi
+
+	if test -s "$last_arg"
+	then
+		cat >&2 "$last_arg"
+	else
+		echo >&2 "<File '$last_arg' is empty>"
+	fi
+
+	return 1
+}
+
 # Call any command "$@" but be more verbose about its
 # failure. This is handy for commands like "test" which do
 # not output anything when they fail.