git

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/*
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 * Whitespace rules
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 *
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 * Copyright (c) 2007 Junio C Hamano
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 */
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#include "git-compat-util.h"
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#include "attr.h"
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#include "strbuf.h"
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#include "ws.h"
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unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
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static struct whitespace_rule {
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	const char *rule_name;
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	unsigned rule_bits;
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	unsigned loosens_error:1,
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		exclude_default:1;
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} whitespace_rule_names[] = {
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	{ "trailing-space", WS_TRAILING_SPACE, 0 },
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	{ "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
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	{ "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
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	{ "cr-at-eol", WS_CR_AT_EOL, 1 },
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	{ "blank-at-eol", WS_BLANK_AT_EOL, 0 },
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	{ "blank-at-eof", WS_BLANK_AT_EOF, 0 },
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	{ "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
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};
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unsigned parse_whitespace_rule(const char *string)
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{
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	unsigned rule = WS_DEFAULT_RULE;
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32
	while (string) {
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		int i;
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		size_t len;
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		const char *ep;
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		const char *arg;
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		int negated = 0;
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		string = string + strspn(string, ", \t\n\r");
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		ep = strchrnul(string, ',');
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		len = ep - string;
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		if (*string == '-') {
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			negated = 1;
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			string++;
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			len--;
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		}
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		if (!len)
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			break;
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		for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
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			if (strncmp(whitespace_rule_names[i].rule_name,
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				    string, len))
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				continue;
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			if (negated)
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				rule &= ~whitespace_rule_names[i].rule_bits;
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			else
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				rule |= whitespace_rule_names[i].rule_bits;
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			break;
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		}
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		if (skip_prefix(string, "tabwidth=", &arg)) {
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			unsigned tabwidth = atoi(arg);
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			if (0 < tabwidth && tabwidth < 0100) {
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				rule &= ~WS_TAB_WIDTH_MASK;
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				rule |= tabwidth;
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			}
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			else
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				warning("tabwidth %.*s out of range",
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					(int)(ep - arg), arg);
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		}
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		string = ep;
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	}
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	if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
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		die("cannot enforce both tab-in-indent and indent-with-non-tab");
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	return rule;
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}
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unsigned whitespace_rule(struct index_state *istate, const char *pathname)
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{
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	static struct attr_check *attr_whitespace_rule;
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	const char *value;
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	if (!attr_whitespace_rule)
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		attr_whitespace_rule = attr_check_initl("whitespace", NULL);
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	git_check_attr(istate, pathname, attr_whitespace_rule);
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	value = attr_whitespace_rule->items[0].value;
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	if (ATTR_TRUE(value)) {
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		/* true (whitespace) */
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		unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
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		int i;
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		for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
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			if (!whitespace_rule_names[i].loosens_error &&
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			    !whitespace_rule_names[i].exclude_default)
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				all_rule |= whitespace_rule_names[i].rule_bits;
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		return all_rule;
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	} else if (ATTR_FALSE(value)) {
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		/* false (-whitespace) */
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		return ws_tab_width(whitespace_rule_cfg);
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	} else if (ATTR_UNSET(value)) {
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		/* reset to default (!whitespace) */
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		return whitespace_rule_cfg;
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	} else {
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		/* string */
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		return parse_whitespace_rule(value);
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	}
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}
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/* The returned string should be freed by the caller. */
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char *whitespace_error_string(unsigned ws)
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{
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	struct strbuf err = STRBUF_INIT;
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	if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
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		strbuf_addstr(&err, "trailing whitespace");
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	else {
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		if (ws & WS_BLANK_AT_EOL)
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			strbuf_addstr(&err, "trailing whitespace");
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		if (ws & WS_BLANK_AT_EOF) {
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			if (err.len)
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				strbuf_addstr(&err, ", ");
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			strbuf_addstr(&err, "new blank line at EOF");
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		}
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	}
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	if (ws & WS_SPACE_BEFORE_TAB) {
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		if (err.len)
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			strbuf_addstr(&err, ", ");
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		strbuf_addstr(&err, "space before tab in indent");
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	}
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	if (ws & WS_INDENT_WITH_NON_TAB) {
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		if (err.len)
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			strbuf_addstr(&err, ", ");
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		strbuf_addstr(&err, "indent with spaces");
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	}
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	if (ws & WS_TAB_IN_INDENT) {
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		if (err.len)
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			strbuf_addstr(&err, ", ");
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		strbuf_addstr(&err, "tab in indent");
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	}
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	return strbuf_detach(&err, NULL);
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}
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/* If stream is non-NULL, emits the line after checking. */
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static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
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				FILE *stream, const char *set,
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				const char *reset, const char *ws)
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{
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	unsigned result = 0;
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	int written = 0;
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	int trailing_whitespace = -1;
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	int trailing_newline = 0;
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	int trailing_carriage_return = 0;
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	int i;
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	/* Logic is simpler if we temporarily ignore the trailing newline. */
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	if (len > 0 && line[len - 1] == '\n') {
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		trailing_newline = 1;
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		len--;
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	}
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	if ((ws_rule & WS_CR_AT_EOL) &&
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	    len > 0 && line[len - 1] == '\r') {
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		trailing_carriage_return = 1;
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		len--;
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	}
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	/* Check for trailing whitespace. */
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	if (ws_rule & WS_BLANK_AT_EOL) {
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		for (i = len - 1; i >= 0; i--) {
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			if (isspace(line[i])) {
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				trailing_whitespace = i;
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				result |= WS_BLANK_AT_EOL;
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			}
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			else
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				break;
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		}
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	}
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	if (trailing_whitespace == -1)
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		trailing_whitespace = len;
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	/* Check indentation */
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	for (i = 0; i < trailing_whitespace; i++) {
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		if (line[i] == ' ')
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			continue;
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		if (line[i] != '\t')
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			break;
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		if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
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			result |= WS_SPACE_BEFORE_TAB;
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			if (stream) {
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				fputs(ws, stream);
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				fwrite(line + written, i - written, 1, stream);
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				fputs(reset, stream);
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				fwrite(line + i, 1, 1, stream);
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			}
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		} else if (ws_rule & WS_TAB_IN_INDENT) {
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			result |= WS_TAB_IN_INDENT;
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			if (stream) {
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				fwrite(line + written, i - written, 1, stream);
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				fputs(ws, stream);
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				fwrite(line + i, 1, 1, stream);
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				fputs(reset, stream);
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			}
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		} else if (stream) {
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			fwrite(line + written, i - written + 1, 1, stream);
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		}
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		written = i + 1;
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	}
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	/* Check for indent using non-tab. */
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	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
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		result |= WS_INDENT_WITH_NON_TAB;
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		if (stream) {
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			fputs(ws, stream);
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			fwrite(line + written, i - written, 1, stream);
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			fputs(reset, stream);
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		}
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		written = i;
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	}
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	if (stream) {
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		/*
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		 * Now the rest of the line starts at "written".
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		 * The non-highlighted part ends at "trailing_whitespace".
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		 */
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		/* Emit non-highlighted (middle) segment. */
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		if (trailing_whitespace - written > 0) {
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			fputs(set, stream);
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			fwrite(line + written,
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			    trailing_whitespace - written, 1, stream);
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			fputs(reset, stream);
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		}
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		/* Highlight errors in trailing whitespace. */
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		if (trailing_whitespace != len) {
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			fputs(ws, stream);
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			fwrite(line + trailing_whitespace,
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			    len - trailing_whitespace, 1, stream);
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			fputs(reset, stream);
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		}
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		if (trailing_carriage_return)
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			fputc('\r', stream);
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		if (trailing_newline)
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			fputc('\n', stream);
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	}
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	return result;
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}
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void ws_check_emit(const char *line, int len, unsigned ws_rule,
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		   FILE *stream, const char *set,
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		   const char *reset, const char *ws)
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{
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	(void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
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}
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unsigned ws_check(const char *line, int len, unsigned ws_rule)
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{
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	return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
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}
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int ws_blank_line(const char *line, int len)
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{
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	/*
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	 * We _might_ want to treat CR differently from other
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	 * whitespace characters when ws_rule has WS_CR_AT_EOL, but
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	 * for now we just use this stupid definition.
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	 */
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	while (len-- > 0) {
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		if (!isspace(*line))
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			return 0;
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		line++;
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	}
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	return 1;
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}
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/* Copy the line onto the end of the strbuf while fixing whitespaces */
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void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
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{
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	/*
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	 * len is number of bytes to be copied from src, starting
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	 * at src.  Typically src[len-1] is '\n', unless this is
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	 * the incomplete last line.
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	 */
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	int i;
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	int add_nl_to_tail = 0;
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	int add_cr_to_tail = 0;
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	int fixed = 0;
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	int last_tab_in_indent = -1;
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	int last_space_in_indent = -1;
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	int need_fix_leading_space = 0;
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	/*
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	 * Strip trailing whitespace
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	 */
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	if (ws_rule & WS_BLANK_AT_EOL) {
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		if (0 < len && src[len - 1] == '\n') {
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			add_nl_to_tail = 1;
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			len--;
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			if (0 < len && src[len - 1] == '\r') {
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				add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
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				len--;
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			}
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		}
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		if (0 < len && isspace(src[len - 1])) {
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			while (0 < len && isspace(src[len-1]))
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				len--;
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			fixed = 1;
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		}
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	}
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	/*
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	 * Check leading whitespaces (indent)
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	 */
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	for (i = 0; i < len; i++) {
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		char ch = src[i];
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		if (ch == '\t') {
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			last_tab_in_indent = i;
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			if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
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			    0 <= last_space_in_indent)
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			    need_fix_leading_space = 1;
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		} else if (ch == ' ') {
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			last_space_in_indent = i;
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			if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
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			    ws_tab_width(ws_rule) <= i - last_tab_in_indent)
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				need_fix_leading_space = 1;
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		} else
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			break;
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	}
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	if (need_fix_leading_space) {
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		/* Process indent ourselves */
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		int consecutive_spaces = 0;
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		int last = last_tab_in_indent + 1;
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		if (ws_rule & WS_INDENT_WITH_NON_TAB) {
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			/* have "last" point at one past the indent */
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			if (last_tab_in_indent < last_space_in_indent)
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				last = last_space_in_indent + 1;
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			else
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				last = last_tab_in_indent + 1;
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		}
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		/*
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		 * between src[0..last-1], strip the funny spaces,
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		 * updating them to tab as needed.
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		 */
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		for (i = 0; i < last; i++) {
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			char ch = src[i];
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			if (ch != ' ') {
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				consecutive_spaces = 0;
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				strbuf_addch(dst, ch);
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			} else {
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				consecutive_spaces++;
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				if (consecutive_spaces == ws_tab_width(ws_rule)) {
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					strbuf_addch(dst, '\t');
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					consecutive_spaces = 0;
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				}
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			}
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		}
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		while (0 < consecutive_spaces--)
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			strbuf_addch(dst, ' ');
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		len -= last;
362
		src += last;
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		fixed = 1;
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	} else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
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		/* Expand tabs into spaces */
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		int start = dst->len;
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		int last = last_tab_in_indent + 1;
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		for (i = 0; i < last; i++) {
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			if (src[i] == '\t')
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				do {
371
					strbuf_addch(dst, ' ');
372
				} while ((dst->len - start) % ws_tab_width(ws_rule));
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			else
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				strbuf_addch(dst, src[i]);
375
		}
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		len -= last;
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		src += last;
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		fixed = 1;
379
	}
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	strbuf_add(dst, src, len);
382
	if (add_cr_to_tail)
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		strbuf_addch(dst, '\r');
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	if (add_nl_to_tail)
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		strbuf_addch(dst, '\n');
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	if (fixed && error_count)
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		(*error_count)++;
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}
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