1 files changed, 375 insertions, 176 deletions

diff --git a/config.c b/config.c
index 62c56099bf..7968ef7566 100644
--- a/config.c
+++ b/config.c
@@ -14,8 +14,10 @@
 #include "quote.h"
 #include "hashmap.h"
 #include "string-list.h"
+#include "object-store.h"
 #include "utf8.h"
 #include "dir.h"
+#include "color.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -102,7 +104,7 @@ static int config_buf_ungetc(int c, struct config_source *conf)
 	if (conf->u.buf.pos > 0) {
 		conf->u.buf.pos--;
 		if (conf->u.buf.buf[conf->u.buf.pos] != c)
-			die("BUG: config_buf can only ungetc the same character");
+			BUG("config_buf can only ungetc the same character");
 		return c;
 	}
 
@@ -189,7 +191,7 @@ static int prepare_include_condition_pattern(struct strbuf *pat)
 		strbuf_realpath(&path, cf->path, 1);
 		slash = find_last_dir_sep(path.buf);
 		if (!slash)
-			die("BUG: how is this possible?");
+			BUG("how is this possible?");
 		strbuf_splice(pat, 0, 1, path.buf, slash - path.buf);
 		prefix = slash - path.buf + 1 /* slash */;
 	} else if (!is_absolute_path(pat->buf))
@@ -653,7 +655,45 @@ static int get_base_var(struct strbuf *name)
 	}
 }
 
-static int git_parse_source(config_fn_t fn, void *data)
+struct parse_event_data {
+	enum config_event_t previous_type;
+	size_t previous_offset;
+	const struct config_options *opts;
+};
+
+static int do_event(enum config_event_t type, struct parse_event_data *data)
+{
+	size_t offset;
+
+	if (!data->opts || !data->opts->event_fn)
+		return 0;
+
+	if (type == CONFIG_EVENT_WHITESPACE &&
+	    data->previous_type == type)
+		return 0;
+
+	offset = cf->do_ftell(cf);
+	/*
+	 * At EOF, the parser always "inserts" an extra '\n', therefore
+	 * the end offset of the event is the current file position, otherwise
+	 * we will already have advanced to the next event.
+	 */
+	if (type != CONFIG_EVENT_EOF)
+		offset--;
+
+	if (data->previous_type != CONFIG_EVENT_EOF &&
+	    data->opts->event_fn(data->previous_type, data->previous_offset,
+				 offset, data->opts->event_fn_data) < 0)
+		return -1;
+
+	data->previous_type = type;
+	data->previous_offset = offset;
+
+	return 0;
+}
+
+static int git_parse_source(config_fn_t fn, void *data,
+			    const struct config_options *opts)
 {
 	int comment = 0;
 	int baselen = 0;
@@ -664,8 +704,15 @@ static int git_parse_source(config_fn_t fn, void *data)
 	/* U+FEFF Byte Order Mark in UTF8 */
 	const char *bomptr = utf8_bom;
 
+	/* For the parser event callback */
+	struct parse_event_data event_data = {
+		CONFIG_EVENT_EOF, 0, opts
+	};
+
 	for (;;) {
-		int c = get_next_char();
+		int c;
+
+		c = get_next_char();
 		if (bomptr && *bomptr) {
 			/* We are at the file beginning; skip UTF8-encoded BOM
 			 * if present. Sane editors won't put this in on their
@@ -682,18 +729,33 @@ static int git_parse_source(config_fn_t fn, void *data)
 			}
 		}
 		if (c == '\n') {
-			if (cf->eof)
+			if (cf->eof) {
+				if (do_event(CONFIG_EVENT_EOF, &event_data) < 0)
+					return -1;
 				return 0;
+			}
+			if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0)
+				return -1;
 			comment = 0;
 			continue;
 		}
-		if (comment || isspace(c))
+		if (comment)
+			continue;
+		if (isspace(c)) {
+			if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0)
+					return -1;
 			continue;
+		}
 		if (c == '#' || c == ';') {
+			if (do_event(CONFIG_EVENT_COMMENT, &event_data) < 0)
+					return -1;
 			comment = 1;
 			continue;
 		}
 		if (c == '[') {
+			if (do_event(CONFIG_EVENT_SECTION, &event_data) < 0)
+					return -1;
+
 			/* Reset prior to determining a new stem */
 			strbuf_reset(var);
 			if (get_base_var(var) < 0 || var->len < 1)
@@ -704,6 +766,10 @@ static int git_parse_source(config_fn_t fn, void *data)
 		}
 		if (!isalpha(c))
 			break;
+
+		if (do_event(CONFIG_EVENT_ENTRY, &event_data) < 0)
+			return -1;
+
 		/*
 		 * Truncate the var name back to the section header
 		 * stem prior to grabbing the suffix part of the name
@@ -715,6 +781,9 @@ static int git_parse_source(config_fn_t fn, void *data)
 			break;
 	}
 
+	if (do_event(CONFIG_EVENT_ERROR, &event_data) < 0)
+		return -1;
+
 	switch (cf->origin_type) {
 	case CONFIG_ORIGIN_BLOB:
 		error_msg = xstrfmt(_("bad config line %d in blob %s"),
@@ -1000,6 +1069,15 @@ int git_config_expiry_date(timestamp_t *timestamp, const char *var, const char *
 	return 0;
 }
 
+int git_config_color(char *dest, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (color_parse(value, dest) < 0)
+		return -1;
+	return 0;
+}
+
 static int git_default_core_config(const char *var, const char *value)
 {
 	/* This needs a better name */
@@ -1156,7 +1234,7 @@ static int git_default_core_config(const char *var, const char *value)
 		}
 		eol_rndtrp_die = git_config_bool(var, value);
 		global_conv_flags_eol = eol_rndtrp_die ?
-			CONV_EOL_RNDTRP_DIE : CONV_EOL_RNDTRP_WARN;
+			CONV_EOL_RNDTRP_DIE : 0;
 		return 0;
 	}
 
@@ -1172,6 +1250,11 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.checkroundtripencoding")) {
+		check_roundtrip_encoding = xstrdup(value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.notesref")) {
 		notes_ref_name = xstrdup(value);
 		return 0;
@@ -1226,6 +1309,11 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.commitgraph")) {
+		core_commit_graph = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.sparsecheckout")) {
 		core_apply_sparse_checkout = git_config_bool(var, value);
 		return 0;
@@ -1365,7 +1453,7 @@ int git_default_config(const char *var, const char *value, void *dummy)
 	if (starts_with(var, "mailmap."))
 		return git_default_mailmap_config(var, value);
 
-	if (starts_with(var, "advice."))
+	if (starts_with(var, "advice.") || starts_with(var, "color.advice"))
 		return git_default_advice_config(var, value);
 
 	if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
@@ -1398,7 +1486,8 @@ int git_default_config(const char *var, const char *value, void *dummy)
  * fgetc, ungetc, ftell of top need to be initialized before calling
  * this function.
  */
-static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
+static int do_config_from(struct config_source *top, config_fn_t fn, void *data,
+			  const struct config_options *opts)
 {
 	int ret;
 
@@ -1410,7 +1499,7 @@ static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
 	strbuf_init(&top->var, 1024);
 	cf = top;
 
-	ret = git_parse_source(fn, data);
+	ret = git_parse_source(fn, data, opts);
 
 	/* pop config-file parsing state stack */
 	strbuf_release(&top->value);
@@ -1423,7 +1512,7 @@ static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
 static int do_config_from_file(config_fn_t fn,
 		const enum config_origin_type origin_type,
 		const char *name, const char *path, FILE *f,
-		void *data)
+		void *data, const struct config_options *opts)
 {
 	struct config_source top;
 	int ret;
@@ -1438,29 +1527,38 @@ static int do_config_from_file(config_fn_t fn,
 	top.do_ftell = config_file_ftell;
 
 	flockfile(f);
-	ret = do_config_from(&top, fn, data);
+	ret = do_config_from(&top, fn, data, opts);
 	funlockfile(f);
 	return ret;
 }
 
 static int git_config_from_stdin(config_fn_t fn, void *data)
 {
-	return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin, data);
+	return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin,
+				   data, NULL);
 }
 
-int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+int git_config_from_file_with_options(config_fn_t fn, const char *filename,
+				      void *data,
+				      const struct config_options *opts)
 {
 	int ret = -1;
 	FILE *f;
 
 	f = fopen_or_warn(filename, "r");
 	if (f) {
-		ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename, filename, f, data);
+		ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename,
+					  filename, f, data, opts);
 		fclose(f);
 	}
 	return ret;
 }
 
+int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+	return git_config_from_file_with_options(fn, filename, data, NULL);
+}
+
 int git_config_from_mem(config_fn_t fn, const enum config_origin_type origin_type,
 			const char *name, const char *buf, size_t len, void *data)
 {
@@ -1477,7 +1575,7 @@ int git_config_from_mem(config_fn_t fn, const enum config_origin_type origin_typ
 	top.do_ungetc = config_buf_ungetc;
 	top.do_ftell = config_buf_ftell;
 
-	return do_config_from(&top, fn, data);
+	return do_config_from(&top, fn, data, NULL);
 }
 
 int git_config_from_blob_oid(config_fn_t fn,
@@ -1717,7 +1815,7 @@ static int configset_add_value(struct config_set *cs, const char *key, const cha
 	l_item->value_index = e->value_list.nr - 1;
 
 	if (!cf)
-		die("BUG: configset_add_value has no source");
+		BUG("configset_add_value has no source");
 	if (cf->name) {
 		kv_info->filename = strintern(cf->name);
 		kv_info->linenr = cf->linenr;
@@ -2075,23 +2173,6 @@ int git_config_get_pathname(const char *key, const char **dest)
 	return repo_config_get_pathname(the_repository, key, dest);
 }
 
-/*
- * Note: This function exists solely to maintain backward compatibility with
- * 'fetch' and 'update_clone' storing configuration in '.gitmodules' and should
- * NOT be used anywhere else.
- *
- * Runs the provided config function on the '.gitmodules' file found in the
- * working directory.
- */
-void config_from_gitmodules(config_fn_t fn, void *data)
-{
-	if (the_repository->worktree) {
-		char *file = repo_worktree_path(the_repository, GITMODULES_FILE);
-		git_config_from_file(fn, file, data);
-		free(file);
-	}
-}
-
 int git_config_get_expiry(const char *key, const char **output)
 {
 	int ret = git_config_get_string_const(key, output);
@@ -2221,96 +2302,111 @@ void git_die_config(const char *key, const char *err, ...)
  * Find all the stuff for git_config_set() below.
  */
 
-static struct {
+struct config_store_data {
 	int baselen;
 	char *key;
 	int do_not_match;
 	regex_t *value_regex;
 	int multi_replace;
-	size_t *offset;
-	unsigned int offset_alloc;
-	enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
-	unsigned int seen;
-} store;
+	struct {
+		size_t begin, end;
+		enum config_event_t type;
+		int is_keys_section;
+	} *parsed;
+	unsigned int parsed_nr, parsed_alloc, *seen, seen_nr, seen_alloc;
+	unsigned int key_seen:1, section_seen:1, is_keys_section:1;
+};
+
+static void config_store_data_clear(struct config_store_data *store)
+{
+	free(store->key);
+	if (store->value_regex != NULL &&
+	    store->value_regex != CONFIG_REGEX_NONE) {
+		regfree(store->value_regex);
+		free(store->value_regex);
+	}
+	free(store->parsed);
+	free(store->seen);
+	memset(store, 0, sizeof(*store));
+}
 
-static int matches(const char *key, const char *value)
+static int matches(const char *key, const char *value,
+		   const struct config_store_data *store)
 {
-	if (strcmp(key, store.key))
+	if (strcmp(key, store->key))
 		return 0; /* not ours */
-	if (!store.value_regex)
+	if (!store->value_regex)
 		return 1; /* always matches */
-	if (store.value_regex == CONFIG_REGEX_NONE)
+	if (store->value_regex == CONFIG_REGEX_NONE)
 		return 0; /* never matches */
 
-	return store.do_not_match ^
-		(value && !regexec(store.value_regex, value, 0, NULL, 0));
+	return store->do_not_match ^
+		(value && !regexec(store->value_regex, value, 0, NULL, 0));
+}
+
+static int store_aux_event(enum config_event_t type,
+			   size_t begin, size_t end, void *data)
+{
+	struct config_store_data *store = data;
+
+	ALLOC_GROW(store->parsed, store->parsed_nr + 1, store->parsed_alloc);
+	store->parsed[store->parsed_nr].begin = begin;
+	store->parsed[store->parsed_nr].end = end;
+	store->parsed[store->parsed_nr].type = type;
+
+	if (type == CONFIG_EVENT_SECTION) {
+		if (cf->var.len < 2 || cf->var.buf[cf->var.len - 1] != '.')
+			return error("invalid section name '%s'", cf->var.buf);
+
+		/* Is this the section we were looking for? */
+		store->is_keys_section =
+			store->parsed[store->parsed_nr].is_keys_section =
+			cf->var.len - 1 == store->baselen &&
+			!strncasecmp(cf->var.buf, store->key, store->baselen);
+		if (store->is_keys_section) {
+			store->section_seen = 1;
+			ALLOC_GROW(store->seen, store->seen_nr + 1,
+				   store->seen_alloc);
+			store->seen[store->seen_nr] = store->parsed_nr;
+		}
+	}
+
+	store->parsed_nr++;
+
+	return 0;
 }
 
 static int store_aux(const char *key, const char *value, void *cb)
 {
-	const char *ep;
-	size_t section_len;
+	struct config_store_data *store = cb;
 
-	switch (store.state) {
-	case KEY_SEEN:
-		if (matches(key, value)) {
-			if (store.seen == 1 && store.multi_replace == 0) {
+	if (store->key_seen) {
+		if (matches(key, value, store)) {
+			if (store->seen_nr == 1 && store->multi_replace == 0) {
 				warning(_("%s has multiple values"), key);
 			}
 
-			ALLOC_GROW(store.offset, store.seen + 1,
-				   store.offset_alloc);
+			ALLOC_GROW(store->seen, store->seen_nr + 1,
+				   store->seen_alloc);
 
-			store.offset[store.seen] = cf->do_ftell(cf);
-			store.seen++;
+			store->seen[store->seen_nr] = store->parsed_nr;
+			store->seen_nr++;
 		}
-		break;
-	case SECTION_SEEN:
+	} else if (store->is_keys_section) {
 		/*
-		 * What we are looking for is in store.key (both
-		 * section and var), and its section part is baselen
-		 * long.  We found key (again, both section and var).
-		 * We would want to know if this key is in the same
-		 * section as what we are looking for.  We already
-		 * know we are in the same section as what should
-		 * hold store.key.
+		 * Do not increment matches yet: this may not be a match, but we
+		 * are in the desired section.
 		 */
-		ep = strrchr(key, '.');
-		section_len = ep - key;
-
-		if ((section_len != store.baselen) ||
-		    memcmp(key, store.key, section_len+1)) {
-			store.state = SECTION_END_SEEN;
-			break;
-		}
+		ALLOC_GROW(store->seen, store->seen_nr + 1, store->seen_alloc);
+		store->seen[store->seen_nr] = store->parsed_nr;
+		store->section_seen = 1;
 
-		/*
-		 * Do not increment matches: this is no match, but we
-		 * just made sure we are in the desired section.
-		 */
-		ALLOC_GROW(store.offset, store.seen + 1,
-			   store.offset_alloc);
-		store.offset[store.seen] = cf->do_ftell(cf);
-		/* fallthru */
-	case SECTION_END_SEEN:
-	case START:
-		if (matches(key, value)) {
-			ALLOC_GROW(store.offset, store.seen + 1,
-				   store.offset_alloc);
-			store.offset[store.seen] = cf->do_ftell(cf);
-			store.state = KEY_SEEN;
-			store.seen++;
-		} else {
-			if (strrchr(key, '.') - key == store.baselen &&
-			      !strncmp(key, store.key, store.baselen)) {
-					store.state = SECTION_SEEN;
-					ALLOC_GROW(store.offset,
-						   store.seen + 1,
-						   store.offset_alloc);
-					store.offset[store.seen] = cf->do_ftell(cf);
-			}
+		if (matches(key, value, store)) {
+			store->seen_nr++;
+			store->key_seen = 1;
 		}
 	}
+
 	return 0;
 }
 
@@ -2322,31 +2418,33 @@ static int write_error(const char *filename)
 	return 4;
 }
 
-static struct strbuf store_create_section(const char *key)
+static struct strbuf store_create_section(const char *key,
+					  const struct config_store_data *store)
 {
 	const char *dot;
 	int i;
 	struct strbuf sb = STRBUF_INIT;
 
-	dot = memchr(key, '.', store.baselen);
+	dot = memchr(key, '.', store->baselen);
 	if (dot) {
 		strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
-		for (i = dot - key + 1; i < store.baselen; i++) {
+		for (i = dot - key + 1; i < store->baselen; i++) {
 			if (key[i] == '"' || key[i] == '\\')
 				strbuf_addch(&sb, '\\');
 			strbuf_addch(&sb, key[i]);
 		}
 		strbuf_addstr(&sb, "\"]\n");
 	} else {
-		strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
+		strbuf_addf(&sb, "[%.*s]\n", store->baselen, key);
 	}
 
 	return sb;
 }
 
-static ssize_t write_section(int fd, const char *key)
+static ssize_t write_section(int fd, const char *key,
+			     const struct config_store_data *store)
 {
-	struct strbuf sb = store_create_section(key);
+	struct strbuf sb = store_create_section(key, store);
 	ssize_t ret;
 
 	ret = write_in_full(fd, sb.buf, sb.len);
@@ -2355,11 +2453,12 @@ static ssize_t write_section(int fd, const char *key)
 	return ret;
 }
 
-static ssize_t write_pair(int fd, const char *key, const char *value)
+static ssize_t write_pair(int fd, const char *key, const char *value,
+			  const struct config_store_data *store)
 {
 	int i;
 	ssize_t ret;
-	int length = strlen(key + store.baselen + 1);
+	int length = strlen(key + store->baselen + 1);
 	const char *quote = "";
 	struct strbuf sb = STRBUF_INIT;
 
@@ -2379,7 +2478,7 @@ static ssize_t write_pair(int fd, const char *key, const char *value)
 		quote = "\"";
 
 	strbuf_addf(&sb, "\t%.*s = %s",
-		    length, key + store.baselen + 1, quote);
+		    length, key + store->baselen + 1, quote);
 
 	for (i = 0; value[i]; i++)
 		switch (value[i]) {
@@ -2405,30 +2504,85 @@ static ssize_t write_pair(int fd, const char *key, const char *value)
 	return ret;
 }
 
-static ssize_t find_beginning_of_line(const char *contents, size_t size,
-	size_t offset_, int *found_bracket)
+/*
+ * If we are about to unset the last key(s) in a section, and if there are
+ * no comments surrounding (or included in) the section, we will want to
+ * extend begin/end to remove the entire section.
+ *
+ * Note: the parameter `seen_ptr` points to the index into the store.seen
+ * array.  * This index may be incremented if a section has more than one
+ * entry (which all are to be removed).
+ */
+static void maybe_remove_section(struct config_store_data *store,
+				 const char *contents,
+				 size_t *begin_offset, size_t *end_offset,
+				 int *seen_ptr)
 {
-	size_t equal_offset = size, bracket_offset = size;
-	ssize_t offset;
+	size_t begin;
+	int i, seen, section_seen = 0;
 
-contline:
-	for (offset = offset_-2; offset > 0
-			&& contents[offset] != '\n'; offset--)
-		switch (contents[offset]) {
-			case '=': equal_offset = offset; break;
-			case ']': bracket_offset = offset; break;
+	/*
+	 * First, ensure that this is the first key, and that there are no
+	 * comments before the entry nor before the section header.
+	 */
+	seen = *seen_ptr;
+	for (i = store->seen[seen]; i > 0; i--) {
+		enum config_event_t type = store->parsed[i - 1].type;
+
+		if (type == CONFIG_EVENT_COMMENT)
+			/* There is a comment before this entry or section */
+			return;
+		if (type == CONFIG_EVENT_ENTRY) {
+			if (!section_seen)
+				/* This is not the section's first entry. */
+				return;
+			/* We encountered no comment before the section. */
+			break;
+		}
+		if (type == CONFIG_EVENT_SECTION) {
+			if (!store->parsed[i - 1].is_keys_section)
+				break;
+			section_seen = 1;
+		}
+	}
+	begin = store->parsed[i].begin;
+
+	/*
+	 * Next, make sure that we are removing he last key(s) in the section,
+	 * and that there are no comments that are possibly about the current
+	 * section.
+	 */
+	for (i = store->seen[seen] + 1; i < store->parsed_nr; i++) {
+		enum config_event_t type = store->parsed[i].type;
+
+		if (type == CONFIG_EVENT_COMMENT)
+			return;
+		if (type == CONFIG_EVENT_SECTION) {
+			if (store->parsed[i].is_keys_section)
+				continue;
+			break;
+		}
+		if (type == CONFIG_EVENT_ENTRY) {
+			if (++seen < store->seen_nr &&
+			    i == store->seen[seen])
+				/* We want to remove this entry, too */
+				continue;
+			/* There is another entry in this section. */
+			return;
 		}
-	if (offset > 0 && contents[offset-1] == '\\') {
-		offset_ = offset;
-		goto contline;
 	}
-	if (bracket_offset < equal_offset) {
-		*found_bracket = 1;
-		offset = bracket_offset+1;
-	} else
-		offset++;
 
-	return offset;
+	/*
+	 * We are really removing the last entry/entries from this section, and
+	 * there are no enclosed or surrounding comments. Remove the entire,
+	 * now-empty section.
+	 */
+	*seen_ptr = seen;
+	*begin_offset = begin;
+	if (i < store->parsed_nr)
+		*end_offset = store->parsed[i].begin;
+	else
+		*end_offset = store->parsed[store->parsed_nr - 1].end;
 }
 
 int git_config_set_in_file_gently(const char *config_filename,
@@ -2489,6 +2643,9 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 	char *filename_buf = NULL;
 	char *contents = NULL;
 	size_t contents_sz;
+	struct config_store_data store;
+
+	memset(&store, 0, sizeof(store));
 
 	/* parse-key returns negative; flip the sign to feed exit(3) */
 	ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
@@ -2507,7 +2664,6 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 	fd = hold_lock_file_for_update(&lock, config_filename, 0);
 	if (fd < 0) {
 		error_errno("could not lock config file %s", config_filename);
-		free(store.key);
 		ret = CONFIG_NO_LOCK;
 		goto out_free;
 	}
@@ -2517,8 +2673,6 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 	 */
 	in_fd = open(config_filename, O_RDONLY);
 	if ( in_fd < 0 ) {
-		free(store.key);
-
 		if ( ENOENT != errno ) {
 			error_errno("opening %s", config_filename);
 			ret = CONFIG_INVALID_FILE; /* same as "invalid config file" */
@@ -2530,14 +2684,16 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 			goto out_free;
 		}
 
-		store.key = (char *)key;
-		if (write_section(fd, key) < 0 ||
-		    write_pair(fd, key, value) < 0)
+		free(store.key);
+		store.key = xstrdup(key);
+		if (write_section(fd, key, &store) < 0 ||
+		    write_pair(fd, key, value, &store) < 0)
 			goto write_err_out;
 	} else {
 		struct stat st;
 		size_t copy_begin, copy_end;
 		int i, new_line = 0;
+		struct config_options opts;
 
 		if (value_regex == NULL)
 			store.value_regex = NULL;
@@ -2554,45 +2710,38 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 			if (regcomp(store.value_regex, value_regex,
 					REG_EXTENDED)) {
 				error("invalid pattern: %s", value_regex);
-				free(store.value_regex);
+				FREE_AND_NULL(store.value_regex);
 				ret = CONFIG_INVALID_PATTERN;
 				goto out_free;
 			}
 		}
 
-		ALLOC_GROW(store.offset, 1, store.offset_alloc);
-		store.offset[0] = 0;
-		store.state = START;
-		store.seen = 0;
+		ALLOC_GROW(store.parsed, 1, store.parsed_alloc);
+		store.parsed[0].end = 0;
+
+		memset(&opts, 0, sizeof(opts));
+		opts.event_fn = store_aux_event;
+		opts.event_fn_data = &store;
 
 		/*
-		 * After this, store.offset will contain the *end* offset
-		 * of the last match, or remain at 0 if no match was found.
+		 * After this, store.parsed will contain offsets of all the
+		 * parsed elements, and store.seen will contain a list of
+		 * matches, as indices into store.parsed.
+		 *
 		 * As a side effect, we make sure to transform only a valid
 		 * existing config file.
 		 */
-		if (git_config_from_file(store_aux, config_filename, NULL)) {
+		if (git_config_from_file_with_options(store_aux,
+						      config_filename,
+						      &store, &opts)) {
 			error("invalid config file %s", config_filename);
-			free(store.key);
-			if (store.value_regex != NULL &&
-			    store.value_regex != CONFIG_REGEX_NONE) {
-				regfree(store.value_regex);
-				free(store.value_regex);
-			}
 			ret = CONFIG_INVALID_FILE;
 			goto out_free;
 		}
 
-		free(store.key);
-		if (store.value_regex != NULL &&
-		    store.value_regex != CONFIG_REGEX_NONE) {
-			regfree(store.value_regex);
-			free(store.value_regex);
-		}
-
 		/* if nothing to unset, or too many matches, error out */
-		if ((store.seen == 0 && value == NULL) ||
-				(store.seen > 1 && multi_replace == 0)) {
+		if ((store.seen_nr == 0 && value == NULL) ||
+		    (store.seen_nr > 1 && multi_replace == 0)) {
 			ret = CONFIG_NOTHING_SET;
 			goto out_free;
 		}
@@ -2623,18 +2772,49 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 			goto out_free;
 		}
 
-		if (store.seen == 0)
-			store.seen = 1;
+		if (store.seen_nr == 0) {
+			if (!store.seen_alloc) {
+				/* Did not see key nor section */
+				ALLOC_GROW(store.seen, 1, store.seen_alloc);
+				store.seen[0] = store.parsed_nr
+					- !!store.parsed_nr;
+			}
+			store.seen_nr = 1;
+		}
 
-		for (i = 0, copy_begin = 0; i < store.seen; i++) {
-			if (store.offset[i] == 0) {
-				store.offset[i] = copy_end = contents_sz;
-			} else if (store.state != KEY_SEEN) {
-				copy_end = store.offset[i];
-			} else
-				copy_end = find_beginning_of_line(
-					contents, contents_sz,
-					store.offset[i]-2, &new_line);
+		for (i = 0, copy_begin = 0; i < store.seen_nr; i++) {
+			size_t replace_end;
+			int j = store.seen[i];
+
+			new_line = 0;
+			if (!store.key_seen) {
+				copy_end = store.parsed[j].end;
+				/* include '\n' when copying section header */
+				if (copy_end > 0 && copy_end < contents_sz &&
+				    contents[copy_end - 1] != '\n' &&
+				    contents[copy_end] == '\n')
+					copy_end++;
+				replace_end = copy_end;
+			} else {
+				replace_end = store.parsed[j].end;
+				copy_end = store.parsed[j].begin;
+				if (!value)
+					maybe_remove_section(&store, contents,
+							     &copy_end,
+							     &replace_end, &i);
+				/*
+				 * Swallow preceding white-space on the same
+				 * line.
+				 */
+				while (copy_end > 0 ) {
+					char c = contents[copy_end - 1];
+
+					if (isspace(c) && c != '\n')
+						copy_end--;
+					else
+						break;
+				}
+			}
 
 			if (copy_end > 0 && contents[copy_end-1] != '\n')
 				new_line = 1;
@@ -2648,16 +2828,16 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 				    write_str_in_full(fd, "\n") < 0)
 					goto write_err_out;
 			}
-			copy_begin = store.offset[i];
+			copy_begin = replace_end;
 		}
 
 		/* write the pair (value == NULL means unset) */
 		if (value != NULL) {
-			if (store.state == START) {
-				if (write_section(fd, key) < 0)
+			if (!store.section_seen) {
+				if (write_section(fd, key, &store) < 0)
 					goto write_err_out;
 			}
-			if (write_pair(fd, key, value) < 0)
+			if (write_pair(fd, key, value, &store) < 0)
 				goto write_err_out;
 		}
 
@@ -2689,6 +2869,7 @@ out_free:
 		munmap(contents, contents_sz);
 	if (in_fd >= 0)
 		close(in_fd);
+	config_store_data_clear(&store);
 	return ret;
 
 write_err_out:
@@ -2781,7 +2962,8 @@ static int section_name_is_ok(const char *name)
 
 /* if new_name == NULL, the section is removed instead */
 static int git_config_copy_or_rename_section_in_file(const char *config_filename,
-				      const char *old_name, const char *new_name, int copy)
+				      const char *old_name,
+				      const char *new_name, int copy)
 {
 	int ret = 0, remove = 0;
 	char *filename_buf = NULL;
@@ -2791,6 +2973,9 @@ static int git_config_copy_or_rename_section_in_file(const char *config_filename
 	FILE *config_file = NULL;
 	struct stat st;
 	struct strbuf copystr = STRBUF_INIT;
+	struct config_store_data store;
+
+	memset(&store, 0, sizeof(store));
 
 	if (new_name && !section_name_is_ok(new_name)) {
 		ret = error("invalid section name: %s", new_name);
@@ -2860,7 +3045,7 @@ static int git_config_copy_or_rename_section_in_file(const char *config_filename
 				}
 				store.baselen = strlen(new_name);
 				if (!copy) {
-					if (write_section(out_fd, new_name) < 0) {
+					if (write_section(out_fd, new_name, &store) < 0) {
 						ret = write_error(get_lock_file_path(&lock));
 						goto out;
 					}
@@ -2881,7 +3066,7 @@ static int git_config_copy_or_rename_section_in_file(const char *config_filename
 						output[0] = '\t';
 					}
 				} else {
-					copystr = store_create_section(new_name);
+					copystr = store_create_section(new_name, &store);
 				}
 			}
 			remove = 0;
@@ -2925,6 +3110,7 @@ out:
 	rollback_lock_file(&lock);
 out_no_rollback:
 	free(filename_buf);
+	config_store_data_clear(&store);
 	return ret;
 }
 
@@ -3006,7 +3192,7 @@ const char *current_config_origin_type(void)
 	else if(cf)
 		type = cf->origin_type;
 	else
-		die("BUG: current_config_origin_type called outside config callback");
+		BUG("current_config_origin_type called outside config callback");
 
 	switch (type) {
 	case CONFIG_ORIGIN_BLOB:
@@ -3020,7 +3206,7 @@ const char *current_config_origin_type(void)
 	case CONFIG_ORIGIN_CMDLINE:
 		return "command line";
 	default:
-		die("BUG: unknown config origin type");
+		BUG("unknown config origin type");
 	}
 }
 
@@ -3032,7 +3218,7 @@ const char *current_config_name(void)
 	else if (cf)
 		name = cf->name;
 	else
-		die("BUG: current_config_name called outside config callback");
+		BUG("current_config_name called outside config callback");
 	return name ? name : "";
 }
 
@@ -3043,3 +3229,16 @@ enum config_scope current_config_scope(void)
 	else
 		return current_parsing_scope;
 }
+
+int lookup_config(const char **mapping, int nr_mapping, const char *var)
+{
+	int i;
+
+	for (i = 0; i < nr_mapping; i++) {
+		const char *name = mapping[i];
+
+		if (name && !strcasecmp(var, name))
+			return i;
+	}
+	return -1;
+}