builtin-apply: teach whitespace_rules

We earlier introduced core.whitespace to allow users to tweak the
definition of what the "whitespace errors" are, for the purpose of diff
output highlighting.  This teaches the same to git-apply, so that the
command can both detect (when --whitespace=warn option is given) and fix
(when --whitespace=fix option is given) as configured.

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

1 files changed, 49 insertions, 19 deletions

diff --git a/builtin-apply.c b/builtin-apply.c
index eb09bfef4..e04b49388 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -910,23 +910,35 @@ static void check_whitespace(const char *line, int len)
 	 * this function.  That is, an addition of an empty line would
 	 * check the '+' here.  Sneaky...
 	 */
-	if (isspace(line[len-2]))
+	if ((whitespace_rule & WS_TRAILING_SPACE) && isspace(line[len-2]))
 		goto error;
 
 	/*
 	 * Make sure that there is no space followed by a tab in
 	 * indentation.
 	 */
-	err = "Space in indent is followed by a tab";
-	for (i = 1; i < len; i++) {
-		if (line[i] == '\t') {
-			if (seen_space)
-				goto error;
-		}
-		else if (line[i] == ' ')
-			seen_space = 1;
-		else
-			break;
+	if (whitespace_rule & WS_SPACE_BEFORE_TAB) {
+		err = "Space in indent is followed by a tab";
+		for (i = 1; i < len; i++) {
+			if (line[i] == '\t') {
+				if (seen_space)
+					goto error;
+			}
+			else if (line[i] == ' ')
+				seen_space = 1;
+			else
+				break;
+		}
+	}
+
+	/*
+	 * Make sure that the indentation does not contain more than
+	 * 8 spaces.
+	 */
+	if ((whitespace_rule & WS_INDENT_WITH_NON_TAB) &&
+	    (8 < len) && !strncmp("+        ", line, 9)) {
+		err = "Indent more than 8 places with spaces";
+		goto error;
 	}
 	return;
 
@@ -1581,7 +1593,8 @@ static int apply_line(char *output, const char *patch, int plen)
 	/*
 	 * Strip trailing whitespace
 	 */
-	if (1 < plen && isspace(patch[plen-1])) {
+	if ((whitespace_rule & WS_TRAILING_SPACE) &&
+	    (1 < plen && isspace(patch[plen-1]))) {
 		if (patch[plen] == '\n')
 			add_nl_to_tail = 1;
 		plen--;
@@ -1597,11 +1610,16 @@ static int apply_line(char *output, const char *patch, int plen)
 		char ch = patch[i];
 		if (ch == '\t') {
 			last_tab_in_indent = i;
-			if (0 <= last_space_in_indent)
+			if ((whitespace_rule & WS_SPACE_BEFORE_TAB) &&
+			    0 <= last_space_in_indent)
+			    need_fix_leading_space = 1;
+		} else if (ch == ' ') {
+			last_space_in_indent = i;
+			if ((whitespace_rule & WS_INDENT_WITH_NON_TAB) &&
+			    last_tab_in_indent < 0 &&
+			    8 <= i)
 				need_fix_leading_space = 1;
 		}
-		else if (ch == ' ')
-			last_space_in_indent = i;
 		else
 			break;
 	}
@@ -1609,11 +1627,21 @@ static int apply_line(char *output, const char *patch, int plen)
 	buf = output;
 	if (need_fix_leading_space) {
 		int consecutive_spaces = 0;
+		int last = last_tab_in_indent + 1;
+
+		if (whitespace_rule & WS_INDENT_WITH_NON_TAB) {
+			/* have "last" point at one past the indent */
+			if (last_tab_in_indent < last_space_in_indent)
+				last = last_space_in_indent + 1;
+			else
+				last = last_tab_in_indent + 1;
+		}
+
 		/*
-		 * between patch[1..last_tab_in_indent] strip the
-		 * funny spaces, updating them to tab as needed.
+		 * between patch[1..last], strip the funny spaces,
+		 * updating them to tab as needed.
 		 */
-		for (i = 1; i < last_tab_in_indent; i++, plen--) {
+		for (i = 1; i < last; i++, plen--) {
 			char ch = patch[i];
 			if (ch != ' ') {
 				consecutive_spaces = 0;
@@ -1626,8 +1654,10 @@ static int apply_line(char *output, const char *patch, int plen)
 				}
 			}
 		}
+		while (0 < consecutive_spaces--)
+			*output++ = ' ';
 		fixed = 1;
-		i = last_tab_in_indent;
+		i = last;
 	}
 	else
 		i = 1;