Trailing whitespace and no newline fix

If a patch adds a new line to the end of a file and this line ends with
one trailing whitespace character and has no newline, then
'--whitespace=fix' currently does not remove that trailing whitespace.

This patch fixes this by removing the check for trailing whitespace at
the end of the line at a hardcoded offset which does not take the
eventual absence of newline into account.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4124-apply-ws-rule.sh

@@ -148,4 +148,22 @@ do
 	done
 done
 
+create_patch () {
+	sed -e "s/_/ /" <<-\EOF
+		diff --git a/target b/target
+		index e69de29..8bd6648 100644
+		--- a/target
+		+++ b/target
+		@@ -0,0 +1 @@
+		+A line with trailing whitespace and no newline_
+		\ No newline at end of file
+	EOF
+}
+
+test_expect_success 'trailing whitespace & no newline at the end of file' '
+	>target &&
+	create_patch | git apply --whitespace=fix - &&
+	grep "newline$" target
+'
+
 test_done

ws.c

@@ -261,9 +261,8 @@ int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *erro
 	/*
 	 * Strip trailing whitespace
 	 */
-	if ((ws_rule & WS_TRAILING_SPACE) &&
+	if (ws_rule & WS_TRAILING_SPACE) {
-	    (2 <= len && isspace(src[len-2]))) {
+		if (1 < len && src[len - 1] == '\n') {
-		if (src[len - 1] == '\n') {
 			add_nl_to_tail = 1;
 			len--;
 			if (1 < len && src[len - 1] == '\r') {