t3920: support CR-eating grep

grep(1) converts CRLF line endings to LF on current MinGW:

   $ uname -sr
   MINGW64_NT-10.0-22621 3.3.6-341.x86_64

   $ printf 'a\r\n' | hexdump.exe -C
   00000000  61 0d 0a                                          |a..|
   00000003

   $ printf 'a\r\n' | grep . | hexdump.exe -C
   00000000  61 0a                                             |a.|
   00000002

Create the intended test file by grepping the original file with LF
line endings and adding CRs explicitly.

The missing CRs went unnoticed because test_cmp on MinGW ignores line
endings since 4d715ac (Windows: a test_cmp that is agnostic to random
LF <> CRLF conversions, 2013-10-26).  Fix this test anyway to avoid
depending on that special test_cmp behavior, especially since this is
the only test that needs it.

Piping the output of grep(1) through append_cr has the side-effect of
ignoring its return value.  That means we no longer need the explicit
"|| true" to support commit messages without a body.

Signed-off-by: René Scharfe <[email protected]>
Acked-by: Philippe Blain <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

t/t3920-crlf-messages.sh

@@ -12,7 +12,7 @@ create_crlf_ref () {
 	cat >.crlf-orig-$branch.txt &&
 	cat .crlf-orig-$branch.txt | append_cr >.crlf-message-$branch.txt &&
 	grep 'Subject' .crlf-orig-$branch.txt | tr '\n' ' ' | sed 's/[ ]*$//' | tr -d '\n' >.crlf-subject-$branch.txt &&
-	{ grep 'Body' .crlf-message-$branch.txt >.crlf-body-$branch.txt || true; } &&
+	grep 'Body' .crlf-orig-$branch.txt | append_cr >.crlf-body-$branch.txt &&
 	LIB_CRLF_BRANCHES="${LIB_CRLF_BRANCHES} ${branch}" &&
 	test_tick &&
 	hash=$(git commit-tree HEAD^{tree} -p HEAD -F .crlf-message-${branch}.txt) &&