diff --git a/Makefile b/Makefile
index 91786ad4b3..7f74610ea7 100644
--- a/Makefile
+++ b/Makefile
@@ -662,6 +662,7 @@ TEST_PROGRAMS_NEED_X += test-example-decorate
 TEST_PROGRAMS_NEED_X += test-fake-ssh
 TEST_PROGRAMS_NEED_X += test-genrandom
 TEST_PROGRAMS_NEED_X += test-hashmap
+TEST_PROGRAMS_NEED_X += test-helper
 TEST_PROGRAMS_NEED_X += test-index-version
 TEST_PROGRAMS_NEED_X += test-lazy-init-name-hash
 TEST_PROGRAMS_NEED_X += test-line-buffer
diff --git a/t/helper/test-helper.c b/t/helper/test-helper.c
new file mode 100644
index 0000000000..1eaf8df925
--- /dev/null
+++ b/t/helper/test-helper.c
@@ -0,0 +1,69 @@
+#include "git-compat-util.h"
+#include "strbuf.h"
+#include "gettext.h"
+#include "parse-options.h"
+
+static const char * const test_helper_usage[] = {
+	N_("test-helper [<options>]"),
+	NULL
+};
+
+static int cmp(int argc, const char **argv)
+{
+	FILE *f0, *f1;
+	struct strbuf b0 = STRBUF_INIT, b1 = STRBUF_INIT;
+
+	if (argc != 3)
+		die("Require exactly 2 arguments, got %d", argc);
+
+	if (!(f0 = !strcmp(argv[1], "-") ? stdin : fopen(argv[1], "r")))
+		return error_errno("could not open '%s'", argv[1]);
+	if (!(f1 = !strcmp(argv[2], "-") ? stdin : fopen(argv[2], "r"))) {
+		fclose(f0);
+		return error_errno("could not open '%s'", argv[2]);
+	}
+
+	for (;;) {
+		int r0 = strbuf_getline(&b0, f0);
+		int r1 = strbuf_getline(&b1, f1);
+
+		if (r0 == EOF) {
+			fclose(f0);
+			fclose(f1);
+			strbuf_release(&b0);
+			strbuf_release(&b1);
+			if (r1 == EOF)
+				return 0;
+			return 1;
+		}
+		if (r1 == EOF || strbuf_cmp(&b0, &b1)) {
+			fclose(f0);
+			fclose(f1);
+			strbuf_release(&b0);
+			strbuf_release(&b1);
+			return 1;
+		}
+	}
+}
+
+int cmd_main(int argc, const char **argv)
+{
+	enum mode {
+		CMP = 1
+	} command = 0;
+	struct option options[] = {
+		OPT_CMDMODE(0, "cmp", &command,
+			N_("compare files (ignoring LF vs CR/LF)"), CMP),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, NULL, options,
+			test_helper_usage,
+			PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
+
+	if (command == CMP)
+		return !!cmp(argc, argv);
+
+	die("unhandled mode");
+}
+
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index ea9a68bbd1..61cfe9b2ae 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -696,7 +696,7 @@ test_expect_code () {
 # - not all diff versions understand "-u"
 
 test_cmp() {
-	$GIT_TEST_CMP "$@"
+	GIT_ALLOC_LIMIT=0 $GIT_TEST_CMP "$@"
 }
 
 # test_cmp_bin - helper to compare binary files
@@ -889,72 +889,6 @@ test_skip_or_die () {
 	esac
 }
 
-# The following mingw_* functions obey POSIX shell syntax, but are actually
-# bash scripts, and are meant to be used only with bash on Windows.
-
-# A test_cmp function that treats LF and CRLF equal and avoids to fork
-# diff when possible.
-mingw_test_cmp () {
-	# Read text into shell variables and compare them. If the results
-	# are different, use regular diff to report the difference.
-	local test_cmp_a= test_cmp_b=
-
-	# When text came from stdin (one argument is '-') we must feed it
-	# to diff.
-	local stdin_for_diff=
-
-	# Since it is difficult to detect the difference between an
-	# empty input file and a failure to read the files, we go straight
-	# to diff if one of the inputs is empty.
-	if test -s "$1" && test -s "$2"
-	then
-		# regular case: both files non-empty
-		mingw_read_file_strip_cr_ test_cmp_a <"$1"
-		mingw_read_file_strip_cr_ test_cmp_b <"$2"
-	elif test -s "$1" && test "$2" = -
-	then
-		# read 2nd file from stdin
-		mingw_read_file_strip_cr_ test_cmp_a <"$1"
-		mingw_read_file_strip_cr_ test_cmp_b
-		stdin_for_diff='<<<"$test_cmp_b"'
-	elif test "$1" = - && test -s "$2"
-	then
-		# read 1st file from stdin
-		mingw_read_file_strip_cr_ test_cmp_a
-		mingw_read_file_strip_cr_ test_cmp_b <"$2"
-		stdin_for_diff='<<<"$test_cmp_a"'
-	fi
-	test -n "$test_cmp_a" &&
-	test -n "$test_cmp_b" &&
-	test "$test_cmp_a" = "$test_cmp_b" ||
-	eval "diff -u \"\$@\" $stdin_for_diff"
-}
-
-# $1 is the name of the shell variable to fill in
-mingw_read_file_strip_cr_ () {
-	# Read line-wise using LF as the line separator
-	# and use IFS to strip CR.
-	local line
-	while :
-	do
-		if IFS=$'\r' read -r -d $'\n' line
-		then
-			# good
-			line=$line$'\n'
-		else
-			# we get here at EOF, but also if the last line
-			# was not terminated by LF; in the latter case,
-			# some text was read
-			if test -z "$line"
-			then
-				# EOF, really
-				break
-			fi
-		fi
-		eval "$1=\$$1\$line"
-	done
-}
-
 # Like "env FOO=BAR some-program", but run inside a subshell, which means
 # it also works for shell functions (though those functions cannot impact
 # the environment outside of the test_env invocation).
diff --git a/t/test-lib.sh b/t/test-lib.sh
index e55ba1d3d0..746ba7bcee 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1035,7 +1035,7 @@ case $uname_s in
 	test_set_prereq NATIVE_CRLF
 	test_set_prereq SED_STRIPS_CR
 	test_set_prereq GREP_STRIPS_CR
-	GIT_TEST_CMP=mingw_test_cmp
+	GIT_TEST_CMP="test-helper --cmp"
 	;;
 *CYGWIN*)
 	test_set_prereq POSIXPERM