ws.c - jrn/git - Git at Google

 /*
  * Whitespace rules
  *
  * Copyright (c) 2007 Junio C Hamano
  */

 #include "cache.h"
 #include "attr.h"

 static struct whitespace_rule {
 	const char *rule_name;
 	unsigned rule_bits;
 	unsigned loosens_error:1,
 		exclude_default:1;
 } whitespace_rule_names[] = {
 	{ "trailing-space", WS_TRAILING_SPACE, 0 },
 	{ "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
 	{ "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
 	{ "cr-at-eol", WS_CR_AT_EOL, 1 },
 	{ "blank-at-eol", WS_BLANK_AT_EOL, 0 },
 	{ "blank-at-eof", WS_BLANK_AT_EOF, 0 },
 	{ "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
 };

 unsigned parse_whitespace_rule(const char *string)
 {
 	unsigned rule = WS_DEFAULT_RULE;

 	while (string) {
 		int i;
 		size_t len;
 		const char *ep;
 		int negated = 0;

 		string = string + strspn(string, ", \t\n\r");
 		ep = strchrnul(string, ',');
 		len = ep - string;

 		if (*string == '-') {
 			negated = 1;
 			string++;
 			len--;
 		}
 		if (!len)
 			break;
 		for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
 			if (strncmp(whitespace_rule_names[i].rule_name,
 				    string, len))
 				continue;
 			if (negated)
 				rule &= ~whitespace_rule_names[i].rule_bits;
 			else
 				rule |= whitespace_rule_names[i].rule_bits;
 			break;
 		}
 		if (strncmp(string, "tabwidth=", 9) == 0) {
 			unsigned tabwidth = atoi(string + 9);
 			if (0 < tabwidth && tabwidth < 0100) {
 				rule &= ~WS_TAB_WIDTH_MASK;
 				rule |= tabwidth;
 			}
 			else
 				warning("tabwidth %.*s out of range",
 					(int)(len - 9), string + 9);
 		}
 		string = ep;
 	}

 	if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
 		die("cannot enforce both tab-in-indent and indent-with-non-tab");
 	return rule;
 }

 static void setup_whitespace_attr_check(struct git_attr_check *check)
 {
 	static struct git_attr *attr_whitespace;

 	if (!attr_whitespace)
 		attr_whitespace = git_attr("whitespace");
 	check[0].attr = attr_whitespace;
 }

 unsigned whitespace_rule(const char *pathname)
 {
 	struct git_attr_check attr_whitespace_rule;

 	setup_whitespace_attr_check(&attr_whitespace_rule);
 	if (!git_check_attr(pathname, 1, &attr_whitespace_rule)) {
 		const char *value;

 		value = attr_whitespace_rule.value;
 		if (ATTR_TRUE(value)) {
 			/* true (whitespace) */
 			unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
 			int i;
 			for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
 				if (!whitespace_rule_names[i].loosens_error &&
 				    !whitespace_rule_names[i].exclude_default)
 					all_rule |= whitespace_rule_names[i].rule_bits;
 			return all_rule;
 		} else if (ATTR_FALSE(value)) {
 			/* false (-whitespace) */
 			return ws_tab_width(whitespace_rule_cfg);
 		} else if (ATTR_UNSET(value)) {
 			/* reset to default (!whitespace) */
 			return whitespace_rule_cfg;
 		} else {
 			/* string */
 			return parse_whitespace_rule(value);
 		}
 	} else {
 		return whitespace_rule_cfg;
 	}
 }

 /* The returned string should be freed by the caller. */
 char *whitespace_error_string(unsigned ws)
 {
 	struct strbuf err = STRBUF_INIT;
 	if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
 		strbuf_addstr(&err, "trailing whitespace");
 	else {
 		if (ws & WS_BLANK_AT_EOL)
 			strbuf_addstr(&err, "trailing whitespace");
 		if (ws & WS_BLANK_AT_EOF) {
 			if (err.len)
 				strbuf_addstr(&err, ", ");
 			strbuf_addstr(&err, "new blank line at EOF");
 		}
 	}
 	if (ws & WS_SPACE_BEFORE_TAB) {
 		if (err.len)
 			strbuf_addstr(&err, ", ");
 		strbuf_addstr(&err, "space before tab in indent");
 	}
 	if (ws & WS_INDENT_WITH_NON_TAB) {
 		if (err.len)
 			strbuf_addstr(&err, ", ");
 		strbuf_addstr(&err, "indent with spaces");
 	}
 	if (ws & WS_TAB_IN_INDENT) {
 		if (err.len)
 			strbuf_addstr(&err, ", ");
 		strbuf_addstr(&err, "tab in indent");
 	}
 	return strbuf_detach(&err, NULL);
 }

 /* If stream is non-NULL, emits the line after checking. */
 static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
 				FILE *stream, const char *set,
 				const char *reset, const char *ws)
 {
 	unsigned result = 0;
 	int written = 0;
 	int trailing_whitespace = -1;
 	int trailing_newline = 0;
 	int trailing_carriage_return = 0;
 	int i;

 	/* Logic is simpler if we temporarily ignore the trailing newline. */
 	if (len > 0 && line[len - 1] == '\n') {
 		trailing_newline = 1;
 		len--;
 	}
 	if ((ws_rule & WS_CR_AT_EOL) &&
 	    len > 0 && line[len - 1] == '\r') {
 		trailing_carriage_return = 1;
 		len--;
 	}

 	/* Check for trailing whitespace. */
 	if (ws_rule & WS_BLANK_AT_EOL) {
 		for (i = len - 1; i >= 0; i--) {
 			if (isspace(line[i])) {
 				trailing_whitespace = i;
 				result |= WS_BLANK_AT_EOL;
 			}
 			else
 				break;
 		}
 	}

 	if (trailing_whitespace == -1)
 		trailing_whitespace = len;

 	/* Check indentation */
 	for (i = 0; i < trailing_whitespace; i++) {
 		if (line[i] == ' ')
 			continue;
 		if (line[i] != '\t')
 			break;
 		if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
 			result |= WS_SPACE_BEFORE_TAB;
 			if (stream) {
 				fputs(ws, stream);
 				fwrite(line + written, i - written, 1, stream);
 				fputs(reset, stream);
 				fwrite(line + i, 1, 1, stream);
 			}
 		} else if (ws_rule & WS_TAB_IN_INDENT) {
 			result |= WS_TAB_IN_INDENT;
 			if (stream) {
 				fwrite(line + written, i - written, 1, stream);
 				fputs(ws, stream);
 				fwrite(line + i, 1, 1, stream);
 				fputs(reset, stream);
 			}
 		} else if (stream) {
 			fwrite(line + written, i - written + 1, 1, stream);
 		}
 		written = i + 1;
 	}

 	/* Check for indent using non-tab. */
 	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
 		result |= WS_INDENT_WITH_NON_TAB;
 		if (stream) {
 			fputs(ws, stream);
 			fwrite(line + written, i - written, 1, stream);
 			fputs(reset, stream);
 		}
 		written = i;
 	}

 	if (stream) {
 		/*
 		 * Now the rest of the line starts at "written".
 		 * The non-highlighted part ends at "trailing_whitespace".
 		 */

 		/* Emit non-highlighted (middle) segment. */
 		if (trailing_whitespace - written > 0) {
 			fputs(set, stream);
 			fwrite(line + written,
 			    trailing_whitespace - written, 1, stream);
 			fputs(reset, stream);
 		}

 		/* Highlight errors in trailing whitespace. */
 		if (trailing_whitespace != len) {
 			fputs(ws, stream);
 			fwrite(line + trailing_whitespace,
 			    len - trailing_whitespace, 1, stream);
 			fputs(reset, stream);
 		}
 		if (trailing_carriage_return)
 			fputc('\r', stream);
 		if (trailing_newline)
 			fputc('\n', stream);
 	}
 	return result;
 }

 void ws_check_emit(const char *line, int len, unsigned ws_rule,
 		   FILE *stream, const char *set,
 		   const char *reset, const char *ws)
 {
 	(void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
 }

 unsigned ws_check(const char *line, int len, unsigned ws_rule)
 {
 	return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
 }

 int ws_blank_line(const char *line, int len, unsigned ws_rule)
 {
 	/*
 	 * We _might_ want to treat CR differently from other
 	 * whitespace characters when ws_rule has WS_CR_AT_EOL, but
 	 * for now we just use this stupid definition.
 	 */
 	while (len-- > 0) {
 		if (!isspace(*line))
 			return 0;
 		line++;
 	}
 	return 1;
 }

 /* Copy the line onto the end of the strbuf while fixing whitespaces */
 void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
 {
 	/*
 	 * len is number of bytes to be copied from src, starting
 	 * at src.  Typically src[len-1] is '\n', unless this is
 	 * the incomplete last line.
 	 */
 	int i;
 	int add_nl_to_tail = 0;
 	int add_cr_to_tail = 0;
 	int fixed = 0;
 	int last_tab_in_indent = -1;
 	int last_space_in_indent = -1;
 	int need_fix_leading_space = 0;

 	/*
 	 * Strip trailing whitespace
 	 */
 	if (ws_rule & WS_BLANK_AT_EOL) {
 		if (0 < len && src[len - 1] == '\n') {
 			add_nl_to_tail = 1;
 			len--;
 			if (0 < len && src[len - 1] == '\r') {
 				add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
 				len--;
 			}
 		}
 		if (0 < len && isspace(src[len - 1])) {
 			while (0 < len && isspace(src[len-1]))
 				len--;
 			fixed = 1;
 		}
 	}

 	/*
 	 * Check leading whitespaces (indent)
 	 */
 	for (i = 0; i < len; i++) {
 		char ch = src[i];
 		if (ch == '\t') {
 			last_tab_in_indent = i;
 			if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
 			    0 <= last_space_in_indent)
 			    need_fix_leading_space = 1;
 		} else if (ch == ' ') {
 			last_space_in_indent = i;
 			if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
 			    ws_tab_width(ws_rule) <= i - last_tab_in_indent)
 				need_fix_leading_space = 1;
 		} else
 			break;
 	}

 	if (need_fix_leading_space) {
 		/* Process indent ourselves */
 		int consecutive_spaces = 0;
 		int last = last_tab_in_indent + 1;

 		if (ws_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 src[0..last-1], strip the funny spaces,
 		 * updating them to tab as needed.
 		 */
 		for (i = 0; i < last; i++) {
 			char ch = src[i];
 			if (ch != ' ') {
 				consecutive_spaces = 0;
 				strbuf_addch(dst, ch);
 			} else {
 				consecutive_spaces++;
 				if (consecutive_spaces == ws_tab_width(ws_rule)) {
 					strbuf_addch(dst, '\t');
 					consecutive_spaces = 0;
 				}
 			}
 		}
 		while (0 < consecutive_spaces--)
 			strbuf_addch(dst, ' ');
 		len -= last;
 		src += last;
 		fixed = 1;
 	} else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
 		/* Expand tabs into spaces */
 		int start = dst->len;
 		int last = last_tab_in_indent + 1;
 		for (i = 0; i < last; i++) {
 			if (src[i] == '\t')
 				do {
 					strbuf_addch(dst, ' ');
 				} while ((dst->len - start) % ws_tab_width(ws_rule));
 			else
 				strbuf_addch(dst, src[i]);
 		}
 		len -= last;
 		src += last;
 		fixed = 1;
 	}

 	strbuf_add(dst, src, len);
 	if (add_cr_to_tail)
 		strbuf_addch(dst, '\r');
 	if (add_nl_to_tail)
 		strbuf_addch(dst, '\n');
 	if (fixed && error_count)
 		(*error_count)++;
 }
	/*
	* Whitespace rules
	*
	* Copyright (c) 2007 Junio C Hamano
	*/

	#include "cache.h"
	#include "attr.h"

	static struct whitespace_rule {
	const char *rule_name;
	unsigned rule_bits;
	unsigned loosens_error:1,
	exclude_default:1;
	} whitespace_rule_names[] = {
	{ "trailing-space", WS_TRAILING_SPACE, 0 },
	{ "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
	{ "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
	{ "cr-at-eol", WS_CR_AT_EOL, 1 },
	{ "blank-at-eol", WS_BLANK_AT_EOL, 0 },
	{ "blank-at-eof", WS_BLANK_AT_EOF, 0 },
	{ "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
	};

	unsigned parse_whitespace_rule(const char *string)
	{
	unsigned rule = WS_DEFAULT_RULE;

	while (string) {
	int i;
	size_t len;
	const char *ep;
	int negated = 0;

	string = string + strspn(string, ", \t\n\r");
	ep = strchrnul(string, ',');
	len = ep - string;

	if (*string == '-') {
	negated = 1;
	string++;
	len--;
	}
	if (!len)
	break;
	for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
	if (strncmp(whitespace_rule_names[i].rule_name,
	string, len))
	continue;
	if (negated)
	rule &= ~whitespace_rule_names[i].rule_bits;
	else
	rule \|= whitespace_rule_names[i].rule_bits;
	break;
	}
	if (strncmp(string, "tabwidth=", 9) == 0) {
	unsigned tabwidth = atoi(string + 9);
	if (0 < tabwidth && tabwidth < 0100) {
	rule &= ~WS_TAB_WIDTH_MASK;
	rule \|= tabwidth;
	}
	else
	warning("tabwidth %.*s out of range",
	(int)(len - 9), string + 9);
	}
	string = ep;
	}

	if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
	die("cannot enforce both tab-in-indent and indent-with-non-tab");
	return rule;
	}

	static void setup_whitespace_attr_check(struct git_attr_check *check)
	{
	static struct git_attr *attr_whitespace;

	if (!attr_whitespace)
	attr_whitespace = git_attr("whitespace");
	check[0].attr = attr_whitespace;
	}

	unsigned whitespace_rule(const char *pathname)
	{
	struct git_attr_check attr_whitespace_rule;

	setup_whitespace_attr_check(&attr_whitespace_rule);
	if (!git_check_attr(pathname, 1, &attr_whitespace_rule)) {
	const char *value;

	value = attr_whitespace_rule.value;
	if (ATTR_TRUE(value)) {
	/* true (whitespace) */
	unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
	int i;
	for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
	if (!whitespace_rule_names[i].loosens_error &&
	!whitespace_rule_names[i].exclude_default)
	all_rule \|= whitespace_rule_names[i].rule_bits;
	return all_rule;
	} else if (ATTR_FALSE(value)) {
	/* false (-whitespace) */
	return ws_tab_width(whitespace_rule_cfg);
	} else if (ATTR_UNSET(value)) {
	/* reset to default (!whitespace) */
	return whitespace_rule_cfg;
	} else {
	/* string */
	return parse_whitespace_rule(value);
	}
	} else {
	return whitespace_rule_cfg;
	}
	}

	/* The returned string should be freed by the caller. */
	char *whitespace_error_string(unsigned ws)
	{
	struct strbuf err = STRBUF_INIT;
	if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
	strbuf_addstr(&err, "trailing whitespace");
	else {
	if (ws & WS_BLANK_AT_EOL)
	strbuf_addstr(&err, "trailing whitespace");
	if (ws & WS_BLANK_AT_EOF) {
	if (err.len)
	strbuf_addstr(&err, ", ");
	strbuf_addstr(&err, "new blank line at EOF");
	}
	}
	if (ws & WS_SPACE_BEFORE_TAB) {
	if (err.len)
	strbuf_addstr(&err, ", ");
	strbuf_addstr(&err, "space before tab in indent");
	}
	if (ws & WS_INDENT_WITH_NON_TAB) {
	if (err.len)
	strbuf_addstr(&err, ", ");
	strbuf_addstr(&err, "indent with spaces");
	}
	if (ws & WS_TAB_IN_INDENT) {
	if (err.len)
	strbuf_addstr(&err, ", ");
	strbuf_addstr(&err, "tab in indent");
	}
	return strbuf_detach(&err, NULL);
	}

	/* If stream is non-NULL, emits the line after checking. */
	static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
	FILE stream, const char set,
	const char reset, const char ws)
	{
	unsigned result = 0;
	int written = 0;
	int trailing_whitespace = -1;
	int trailing_newline = 0;
	int trailing_carriage_return = 0;
	int i;

	/* Logic is simpler if we temporarily ignore the trailing newline. */
	if (len > 0 && line[len - 1] == '\n') {
	trailing_newline = 1;
	len--;
	}
	if ((ws_rule & WS_CR_AT_EOL) &&
	len > 0 && line[len - 1] == '\r') {
	trailing_carriage_return = 1;
	len--;
	}

	/* Check for trailing whitespace. */
	if (ws_rule & WS_BLANK_AT_EOL) {
	for (i = len - 1; i >= 0; i--) {
	if (isspace(line[i])) {
	trailing_whitespace = i;
	result \|= WS_BLANK_AT_EOL;
	}
	else
	break;
	}
	}

	if (trailing_whitespace == -1)
	trailing_whitespace = len;

	/* Check indentation */
	for (i = 0; i < trailing_whitespace; i++) {
	if (line[i] == ' ')
	continue;
	if (line[i] != '\t')
	break;
	if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
	result \|= WS_SPACE_BEFORE_TAB;
	if (stream) {
	fputs(ws, stream);
	fwrite(line + written, i - written, 1, stream);
	fputs(reset, stream);
	fwrite(line + i, 1, 1, stream);
	}
	} else if (ws_rule & WS_TAB_IN_INDENT) {
	result \|= WS_TAB_IN_INDENT;
	if (stream) {
	fwrite(line + written, i - written, 1, stream);
	fputs(ws, stream);
	fwrite(line + i, 1, 1, stream);
	fputs(reset, stream);
	}
	} else if (stream) {
	fwrite(line + written, i - written + 1, 1, stream);
	}
	written = i + 1;
	}

	/* Check for indent using non-tab. */
	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
	result \|= WS_INDENT_WITH_NON_TAB;
	if (stream) {
	fputs(ws, stream);
	fwrite(line + written, i - written, 1, stream);
	fputs(reset, stream);
	}
	written = i;
	}

	if (stream) {
	/*
	* Now the rest of the line starts at "written".
	* The non-highlighted part ends at "trailing_whitespace".
	*/

	/* Emit non-highlighted (middle) segment. */
	if (trailing_whitespace - written > 0) {
	fputs(set, stream);
	fwrite(line + written,
	trailing_whitespace - written, 1, stream);
	fputs(reset, stream);
	}

	/* Highlight errors in trailing whitespace. */
	if (trailing_whitespace != len) {
	fputs(ws, stream);
	fwrite(line + trailing_whitespace,
	len - trailing_whitespace, 1, stream);
	fputs(reset, stream);
	}
	if (trailing_carriage_return)
	fputc('\r', stream);
	if (trailing_newline)
	fputc('\n', stream);
	}
	return result;
	}

	void ws_check_emit(const char *line, int len, unsigned ws_rule,
	FILE stream, const char set,
	const char reset, const char ws)
	{
	(void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
	}

	unsigned ws_check(const char *line, int len, unsigned ws_rule)
	{
	return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
	}

	int ws_blank_line(const char *line, int len, unsigned ws_rule)
	{
	/*
	* We _might_ want to treat CR differently from other
	* whitespace characters when ws_rule has WS_CR_AT_EOL, but
	* for now we just use this stupid definition.
	*/
	while (len-- > 0) {
	if (!isspace(*line))
	return 0;
	line++;
	}
	return 1;
	}

	/* Copy the line onto the end of the strbuf while fixing whitespaces */
	void ws_fix_copy(struct strbuf dst, const char src, int len, unsigned ws_rule, int *error_count)
	{
	/*
	* len is number of bytes to be copied from src, starting
	* at src. Typically src[len-1] is '\n', unless this is
	* the incomplete last line.
	*/
	int i;
	int add_nl_to_tail = 0;
	int add_cr_to_tail = 0;
	int fixed = 0;
	int last_tab_in_indent = -1;
	int last_space_in_indent = -1;
	int need_fix_leading_space = 0;

	/*
	* Strip trailing whitespace
	*/
	if (ws_rule & WS_BLANK_AT_EOL) {
	if (0 < len && src[len - 1] == '\n') {
	add_nl_to_tail = 1;
	len--;
	if (0 < len && src[len - 1] == '\r') {
	add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
	len--;
	}
	}
	if (0 < len && isspace(src[len - 1])) {
	while (0 < len && isspace(src[len-1]))
	len--;
	fixed = 1;
	}
	}

	/*
	* Check leading whitespaces (indent)
	*/
	for (i = 0; i < len; i++) {
	char ch = src[i];
	if (ch == '\t') {
	last_tab_in_indent = i;
	if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
	0 <= last_space_in_indent)
	need_fix_leading_space = 1;
	} else if (ch == ' ') {
	last_space_in_indent = i;
	if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
	ws_tab_width(ws_rule) <= i - last_tab_in_indent)
	need_fix_leading_space = 1;
	} else
	break;
	}

	if (need_fix_leading_space) {
	/* Process indent ourselves */
	int consecutive_spaces = 0;
	int last = last_tab_in_indent + 1;

	if (ws_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 src[0..last-1], strip the funny spaces,
	* updating them to tab as needed.
	*/
	for (i = 0; i < last; i++) {
	char ch = src[i];
	if (ch != ' ') {
	consecutive_spaces = 0;
	strbuf_addch(dst, ch);
	} else {
	consecutive_spaces++;
	if (consecutive_spaces == ws_tab_width(ws_rule)) {
	strbuf_addch(dst, '\t');
	consecutive_spaces = 0;
	}
	}
	}
	while (0 < consecutive_spaces--)
	strbuf_addch(dst, ' ');
	len -= last;
	src += last;
	fixed = 1;
	} else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
	/* Expand tabs into spaces */
	int start = dst->len;
	int last = last_tab_in_indent + 1;
	for (i = 0; i < last; i++) {
	if (src[i] == '\t')
	do {
	strbuf_addch(dst, ' ');
	} while ((dst->len - start) % ws_tab_width(ws_rule));
	else
	strbuf_addch(dst, src[i]);
	}
	len -= last;
	src += last;
	fixed = 1;
	}

	strbuf_add(dst, src, len);
	if (add_cr_to_tail)
	strbuf_addch(dst, '\r');
	if (add_nl_to_tail)
	strbuf_addch(dst, '\n');
	if (fixed && error_count)
	(*error_count)++;
	}