whitespace: symbolic links usually lack LF at the end

For a patch that touches a symbolic link, it is perfectly normal
that the contents ends with "\ No newline at end of file".  The
checks introduced recently to detect incomplete lines (i.e., a text
file that lack the newline on its final line) should not trigger.

Disable the check early for symbolic links, both in "git apply" and
"git diff" and test them.  For "git apply", we check only when the
postimage is a symbolic link regardless of the preimage, and we only
care about preimage when applying in reverse.  Similarly, "git diff"
would warn only when the postimage is a symbolic link, or the
preimage when running "git diff -R".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 20 insertions, 2 deletions

diff --git a/diff.c b/diff.c
index 7b7cd50dc2..9e4b92ed69 100644
--- a/diff.c
+++ b/diff.c
@@ -1834,6 +1834,7 @@ static void emit_rewrite_diff(const char *name_a,
 	const char *a_prefix, *b_prefix;
 	char *data_one, *data_two;
 	size_t size_one, size_two;
+	unsigned ws_rule;
 	struct emit_callback ecbdata;
 	struct strbuf out = STRBUF_INIT;
 
@@ -1856,9 +1857,15 @@ static void emit_rewrite_diff(const char *name_a,
 	size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
 	size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
 
+	ws_rule = whitespace_rule(o->repo->index, name_b);
+
+	/* symlink being an incomplete line is not a news */
+	if (DIFF_FILE_VALID(two) && S_ISLNK(two->mode))
+		ws_rule &= ~WS_INCOMPLETE_LINE;
+
 	memset(&ecbdata, 0, sizeof(ecbdata));
 	ecbdata.color_diff = o->use_color;
-	ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
+	ecbdata.ws_rule = ws_rule;
 	ecbdata.opt = o;
 	if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 		mmfile_t mf1, mf2;
@@ -3762,6 +3769,7 @@ static void builtin_diff(const char *name_a,
 		xpparam_t xpp;
 		xdemitconf_t xecfg;
 		struct emit_callback ecbdata;
+		unsigned ws_rule;
 		const struct userdiff_funcname *pe;
 
 		if (must_show_header) {
@@ -3773,6 +3781,12 @@ static void builtin_diff(const char *name_a,
 		mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
 		mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
 
+		ws_rule = whitespace_rule(o->repo->index, name_b);
+
+		/* symlink being an incomplete line is not a news */
+		if (DIFF_FILE_VALID(two) && S_ISLNK(two->mode))
+			ws_rule &= ~WS_INCOMPLETE_LINE;
+
 		pe = diff_funcname_pattern(o, one);
 		if (!pe)
 			pe = diff_funcname_pattern(o, two);
@@ -3784,7 +3798,7 @@ static void builtin_diff(const char *name_a,
 			lbl[0] = NULL;
 		ecbdata.label_path = lbl;
 		ecbdata.color_diff = o->use_color;
-		ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
+		ecbdata.ws_rule = ws_rule;
 		if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
 			check_blank_at_eof(&mf1, &mf2, &ecbdata);
 		ecbdata.opt = o;
@@ -3991,6 +4005,10 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 	data.ws_rule = whitespace_rule(o->repo->index, attr_path);
 	data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
 
+	/* symlink being an incomplete line is not a news */
+	if (DIFF_FILE_VALID(two) && S_ISLNK(two->mode))
+		data.ws_rule &= ~WS_INCOMPLETE_LINE;
+
 	if (fill_mmfile(o->repo, &mf1, one) < 0 ||
 	    fill_mmfile(o->repo, &mf2, two) < 0)
 		die("unable to read files to diff");