Merge branch 'tb/apply-with-crlf' into maint

"git apply" that is used as a better "patch -p1" failed to apply a
taken from a file with CRLF line endings to a file with CRLF line
endings.  The root cause was because it misused convert_to_git()
that tried to do "safe-crlf" processing by looking at the index
entry at the same path, which is a nonsense---in that mode, "apply"
is not working on the data in (or derived from) the index at all.
This has been fixed.

* tb/apply-with-crlf:
  apply: file commited with CRLF should roundtrip diff and apply
  convert: add SAFE_CRLF_KEEP_CRLF

apply.c

@@ -220,6 +220,7 @@ struct patch {
 	unsigned int recount:1;
 	unsigned int conflicted_threeway:1;
 	unsigned int direct_to_threeway:1;
+	unsigned int crlf_in_old:1;
 	struct fragment *fragments;
 	char *result;
 	size_t resultsize;
@@ -1662,6 +1663,19 @@ static void check_whitespace(struct apply_state *state,
 	record_ws_error(state, result, line + 1, len - 2, state->linenr);
 }
 
+/*
+ * Check if the patch has context lines with CRLF or
+ * the patch wants to remove lines with CRLF.
+ */
+static void check_old_for_crlf(struct patch *patch, const char *line, int len)
+{
+	if (len >= 2 && line[len-1] == '\n' && line[len-2] == '\r') {
+		patch->ws_rule |= WS_CR_AT_EOL;
+		patch->crlf_in_old = 1;
+	}
+}
+
+
 /*
  * Parse a unified diff. Note that this really needs to parse each
  * fragment separately, since the only way to know the difference
@@ -1712,11 +1726,14 @@ static int parse_fragment(struct apply_state *state,
 			if (!deleted && !added)
 				leading++;
 			trailing++;
+			check_old_for_crlf(patch, line, len);
 			if (!state->apply_in_reverse &&
 			    state->ws_error_action == correct_ws_error)
 				check_whitespace(state, line, len, patch->ws_rule);
 			break;
 		case '-':
+			if (!state->apply_in_reverse)
+				check_old_for_crlf(patch, line, len);
 			if (state->apply_in_reverse &&
 			    state->ws_error_action != nowarn_ws_error)
 				check_whitespace(state, line, len, patch->ws_rule);
@@ -1725,6 +1742,8 @@ static int parse_fragment(struct apply_state *state,
 			trailing = 0;
 			break;
 		case '+':
+			if (state->apply_in_reverse)
+				check_old_for_crlf(patch, line, len);
 			if (!state->apply_in_reverse &&
 			    state->ws_error_action != nowarn_ws_error)
 				check_whitespace(state, line, len, patch->ws_rule);
@@ -2268,8 +2287,11 @@ static void show_stats(struct apply_state *state, struct patch *patch)
 		add, pluses, del, minuses);
 }
 
-static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
+static int read_old_data(struct stat *st, struct patch *patch,
+			 const char *path, struct strbuf *buf)
 {
+	enum safe_crlf safe_crlf = patch->crlf_in_old ?
+		SAFE_CRLF_KEEP_CRLF : SAFE_CRLF_RENORMALIZE;
 	switch (st->st_mode & S_IFMT) {
 	case S_IFLNK:
 		if (strbuf_readlink(buf, path, st->st_size) < 0)
@@ -2278,7 +2300,15 @@ static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
 	case S_IFREG:
 		if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
 			return error(_("unable to open or read %s"), path);
-		convert_to_git(&the_index, path, buf->buf, buf->len, buf, 0);
+		/*
+		 * "git apply" without "--index/--cached" should never look
+		 * at the index; the target file may not have been added to
+		 * the index yet, and we may not even be in any Git repository.
+		 * Pass NULL to convert_to_git() to stress this; the function
+		 * should never look at the index when explicit crlf option
+		 * is given.
+		 */
+		convert_to_git(NULL, path, buf->buf, buf->len, buf, safe_crlf);
 		return 0;
 	default:
 		return -1;
@@ -3381,6 +3411,7 @@ static int load_patch_target(struct apply_state *state,
 			     struct strbuf *buf,
 			     const struct cache_entry *ce,
 			     struct stat *st,
+			     struct patch *patch,
 			     const char *name,
 			     unsigned expected_mode)
 {
@@ -3396,7 +3427,7 @@ static int load_patch_target(struct apply_state *state,
 		} else if (has_symlink_leading_path(name, strlen(name))) {
 			return error(_("reading from '%s' beyond a symbolic link"), name);
 		} else {
-			if (read_old_data(st, name, buf))
+			if (read_old_data(st, patch, name, buf))
 				return error(_("failed to read %s"), name);
 		}
 	}
@@ -3429,7 +3460,7 @@ static int load_preimage(struct apply_state *state,
 		/* We have a patched copy in memory; use that. */
 		strbuf_add(&buf, previous->result, previous->resultsize);
 	} else {
-		status = load_patch_target(state, &buf, ce, st,
+		status = load_patch_target(state, &buf, ce, st, patch,
 					   patch->old_name, patch->old_mode);
 		if (status < 0)
 			return status;
@@ -3517,7 +3548,7 @@ static int load_current(struct apply_state *state,
 	if (verify_index_match(ce, &st))
 		return error(_("%s: does not match index"), name);
 
-	status = load_patch_target(state, &buf, ce, &st, name, mode);
+	status = load_patch_target(state, &buf, ce, &st, patch, name, mode);
 	if (status < 0)
 		return status;
 	else if (status)

convert.c

@@ -1133,10 +1133,12 @@ int convert_to_git(const struct index_state *istate,
 		src = dst->buf;
 		len = dst->len;
 	}
-	ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, checksafe);
-	if (ret && dst) {
-		src = dst->buf;
-		len = dst->len;
+	if (checksafe != SAFE_CRLF_KEEP_CRLF) {
+		ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, checksafe);
+		if (ret && dst) {
+			src = dst->buf;
+			len = dst->len;
+		}
 	}
 	return ret | ident_to_git(path, src, len, dst, ca.ident);
 }

convert.h

@@ -12,7 +12,8 @@ enum safe_crlf {
 	SAFE_CRLF_FALSE = 0,
 	SAFE_CRLF_FAIL = 1,
 	SAFE_CRLF_WARN = 2,
-	SAFE_CRLF_RENORMALIZE = 3
+	SAFE_CRLF_RENORMALIZE = 3,
+	SAFE_CRLF_KEEP_CRLF = 4
 };
 
 extern enum safe_crlf safe_crlf;

t/t4124-apply-ws-rule.sh

@@ -467,21 +467,42 @@ test_expect_success 'same, but with CR-LF line endings && cr-at-eol set' '
 	test_cmp one expect
 '
 
-test_expect_success 'same, but with CR-LF line endings && cr-at-eol unset' '
+test_expect_success 'CR-LF line endings && add line && text=auto' '
 	git config --unset core.whitespace &&
 	printf "a\r\n" >one &&
-	printf "b\r\n" >>one &&
-	printf "c\r\n" >>one &&
 	cp one save-one &&
-	printf "                 \r\n" >>one &&
 	git add one &&
+	printf "b\r\n" >>one &&
 	cp one expect &&
-	printf "d\r\n" >>one &&
 	git diff -- one >patch &&
 	mv save-one one &&
-	echo d >>expect &&
+	echo "one text=auto" >.gitattributes &&
+	git apply patch &&
+	test_cmp one expect
+'
 
-	git apply --ignore-space-change --whitespace=fix patch &&
+test_expect_success 'CR-LF line endings && change line && text=auto' '
+	printf "a\r\n" >one &&
+	cp one save-one &&
+	git add one &&
+	printf "b\r\n" >one &&
+	cp one expect &&
+	git diff -- one >patch &&
+	mv save-one one &&
+	echo "one text=auto" >.gitattributes &&
+	git apply patch &&
+	test_cmp one expect
+'
+
+test_expect_success 'LF in repo, CRLF in worktree && change line && text=auto' '
+	printf "a\n" >one &&
+	git add one &&
+	printf "b\r\n" >one &&
+	git diff -- one >patch &&
+	printf "a\r\n" >one &&
+	echo "one text=auto" >.gitattributes &&
+	git -c core.eol=CRLF apply patch &&
+	printf "b\r\n" >expect &&
 	test_cmp one expect
 '