1 files changed, 452 insertions, 82 deletions

diff --git a/rerere.c b/rerere.c
index 29f95f657d..a6a5cd57be 100644
--- a/rerere.c
+++ b/rerere.c
@@ -1,8 +1,16 @@
 #include "cache.h"
 #include "string-list.h"
 #include "rerere.h"
-#include "xdiff/xdiff.h"
 #include "xdiff-interface.h"
+#include "dir.h"
+#include "resolve-undo.h"
+#include "ll-merge.h"
+#include "attr.h"
+
+#define RESOLVED 0
+#define PUNTED 1
+#define THREE_STAGED 2
+void *RERERE_RESOLVED = &RERERE_RESOLVED;
 
 /* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
 static int rerere_enabled = -1;
@@ -17,7 +25,7 @@ const char *rerere_path(const char *hex, const char *file)
 	return git_path("rr-cache/%s/%s", hex, file);
 }
 
-int has_rerere_resolution(const char *hex)
+static int has_rerere_resolution(const char *hex)
 {
 	struct stat st;
 	return !stat(rerere_path(hex, "postimage"), &st);
@@ -39,11 +47,17 @@ static void read_rr(struct string_list *rr)
 		name = xstrdup(buf);
 		if (fgetc(in) != '\t')
 			die("corrupt MERGE_RR");
-		for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
-			; /* do nothing */
+		for (i = 0; i < sizeof(buf); i++) {
+			int c = fgetc(in);
+			if (c < 0)
+				die("corrupt MERGE_RR");
+			buf[i] = c;
+			if (c == 0)
+				 break;
+		}
 		if (i == sizeof(buf))
 			die("filename too long");
-		string_list_insert(buf, rr)->util = name;
+		string_list_insert(rr, buf)->util = name;
 	}
 	fclose(in);
 }
@@ -83,61 +97,106 @@ static inline void ferr_puts(const char *s, FILE *fp, int *err)
 	ferr_write(s, strlen(s), fp, err);
 }
 
-static int handle_file(const char *path,
-	 unsigned char *sha1, const char *output)
+struct rerere_io {
+	int (*getline)(struct strbuf *, struct rerere_io *);
+	FILE *output;
+	int wrerror;
+	/* some more stuff */
+};
+
+static void rerere_io_putstr(const char *str, struct rerere_io *io)
+{
+	if (io->output)
+		ferr_puts(str, io->output, &io->wrerror);
+}
+
+static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
+{
+	char buf[64];
+
+	while (size) {
+		if (size < sizeof(buf) - 2) {
+			memset(buf, ch, size);
+			buf[size] = '\n';
+			buf[size + 1] = '\0';
+			size = 0;
+		} else {
+			int sz = sizeof(buf) - 1;
+			if (size <= sz)
+				sz -= (sz - size) + 1;
+			memset(buf, ch, sz);
+			buf[sz] = '\0';
+			size -= sz;
+		}
+		rerere_io_putstr(buf, io);
+	}
+}
+
+static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
+{
+	if (io->output)
+		ferr_write(mem, sz, io->output, &io->wrerror);
+}
+
+struct rerere_io_file {
+	struct rerere_io io;
+	FILE *input;
+};
+
+static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
+{
+	struct rerere_io_file *io = (struct rerere_io_file *)io_;
+	return strbuf_getwholeline(sb, io->input, '\n');
+}
+
+static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
+{
+	while (marker_size--)
+		if (*buf++ != marker_char)
+			return 0;
+	if (want_sp && *buf != ' ')
+		return 0;
+	return isspace(*buf);
+}
+
+static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
 {
 	git_SHA_CTX ctx;
-	char buf[1024];
 	int hunk_no = 0;
 	enum {
-		RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL,
+		RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
 	} hunk = RR_CONTEXT;
 	struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
-	FILE *f = fopen(path, "r");
-	FILE *out = NULL;
-	int wrerror = 0;
-
-	if (!f)
-		return error("Could not open %s", path);
-
-	if (output) {
-		out = fopen(output, "w");
-		if (!out) {
-			fclose(f);
-			return error("Could not write %s", output);
-		}
-	}
+	struct strbuf buf = STRBUF_INIT;
 
 	if (sha1)
 		git_SHA1_Init(&ctx);
 
-	while (fgets(buf, sizeof(buf), f)) {
-		if (!prefixcmp(buf, "<<<<<<< ")) {
+	while (!io->getline(&buf, io)) {
+		if (is_cmarker(buf.buf, '<', marker_size, 1)) {
 			if (hunk != RR_CONTEXT)
 				goto bad;
 			hunk = RR_SIDE_1;
-		} else if (!prefixcmp(buf, "|||||||") && isspace(buf[7])) {
+		} else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
 			if (hunk != RR_SIDE_1)
 				goto bad;
 			hunk = RR_ORIGINAL;
-		} else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
+		} else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
 			if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
 				goto bad;
 			hunk = RR_SIDE_2;
-		} else if (!prefixcmp(buf, ">>>>>>> ")) {
+		} else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
 			if (hunk != RR_SIDE_2)
 				goto bad;
 			if (strbuf_cmp(&one, &two) > 0)
 				strbuf_swap(&one, &two);
 			hunk_no++;
 			hunk = RR_CONTEXT;
-			if (out) {
-				ferr_puts("<<<<<<<\n", out, &wrerror);
-				ferr_write(one.buf, one.len, out, &wrerror);
-				ferr_puts("=======\n", out, &wrerror);
-				ferr_write(two.buf, two.len, out, &wrerror);
-				ferr_puts(">>>>>>>\n", out, &wrerror);
-			}
+			rerere_io_putconflict('<', marker_size, io);
+			rerere_io_putmem(one.buf, one.len, io);
+			rerere_io_putconflict('=', marker_size, io);
+			rerere_io_putmem(two.buf, two.len, io);
+			rerere_io_putconflict('>', marker_size, io);
 			if (sha1) {
 				git_SHA1_Update(&ctx, one.buf ? one.buf : "",
 					    one.len + 1);
@@ -147,13 +206,13 @@ static int handle_file(const char *path,
 			strbuf_reset(&one);
 			strbuf_reset(&two);
 		} else if (hunk == RR_SIDE_1)
-			strbuf_addstr(&one, buf);
+			strbuf_addstr(&one, buf.buf);
 		else if (hunk == RR_ORIGINAL)
 			; /* discard */
 		else if (hunk == RR_SIDE_2)
-			strbuf_addstr(&two, buf);
-		else if (out)
-			ferr_puts(buf, out, &wrerror);
+			strbuf_addstr(&two, buf.buf);
+		else
+			rerere_io_putstr(buf.buf, io);
 		continue;
 	bad:
 		hunk = 99; /* force error exit */
@@ -161,41 +220,210 @@ static int handle_file(const char *path,
 	}
 	strbuf_release(&one);
 	strbuf_release(&two);
+	strbuf_release(&buf);
 
-	fclose(f);
-	if (wrerror)
-		error("There were errors while writing %s (%s)",
-		      path, strerror(wrerror));
-	if (out && fclose(out))
-		wrerror = error("Failed to flush %s: %s",
-				path, strerror(errno));
 	if (sha1)
 		git_SHA1_Final(sha1, &ctx);
-	if (hunk != RR_CONTEXT) {
+	if (hunk != RR_CONTEXT)
+		return -1;
+	return hunk_no;
+}
+
+static int handle_file(const char *path, unsigned char *sha1, const char *output)
+{
+	int hunk_no = 0;
+	struct rerere_io_file io;
+	int marker_size = ll_merge_marker_size(path);
+
+	memset(&io, 0, sizeof(io));
+	io.io.getline = rerere_file_getline;
+	io.input = fopen(path, "r");
+	io.io.wrerror = 0;
+	if (!io.input)
+		return error("Could not open %s", path);
+
+	if (output) {
+		io.io.output = fopen(output, "w");
+		if (!io.io.output) {
+			fclose(io.input);
+			return error("Could not write %s", output);
+		}
+	}
+
+	hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
+
+	fclose(io.input);
+	if (io.io.wrerror)
+		error("There were errors while writing %s (%s)",
+		      path, strerror(io.io.wrerror));
+	if (io.io.output && fclose(io.io.output))
+		io.io.wrerror = error("Failed to flush %s: %s",
+				      path, strerror(errno));
+
+	if (hunk_no < 0) {
 		if (output)
 			unlink_or_warn(output);
 		return error("Could not parse conflict hunks in %s", path);
 	}
-	if (wrerror)
+	if (io.io.wrerror)
 		return -1;
 	return hunk_no;
 }
 
-static int find_conflict(struct string_list *conflict)
+struct rerere_io_mem {
+	struct rerere_io io;
+	struct strbuf input;
+};
+
+static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
 {
-	int i;
-	if (read_cache() < 0)
-		return error("Could not read index");
-	for (i = 0; i+1 < active_nr; i++) {
+	struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
+	char *ep;
+	size_t len;
+
+	strbuf_release(sb);
+	if (!io->input.len)
+		return -1;
+	ep = strchrnul(io->input.buf, '\n');
+	if (*ep == '\n')
+		ep++;
+	len = ep - io->input.buf;
+	strbuf_add(sb, io->input.buf, len);
+	strbuf_remove(&io->input, 0, len);
+	return 0;
+}
+
+static int handle_cache(const char *path, unsigned char *sha1, const char *output)
+{
+	mmfile_t mmfile[3];
+	mmbuffer_t result = {NULL, 0};
+	struct cache_entry *ce;
+	int pos, len, i, hunk_no;
+	struct rerere_io_mem io;
+	int marker_size = ll_merge_marker_size(path);
+
+	/*
+	 * Reproduce the conflicted merge in-core
+	 */
+	len = strlen(path);
+	pos = cache_name_pos(path, len);
+	if (0 <= pos)
+		return -1;
+	pos = -pos - 1;
+
+	for (i = 0; i < 3; i++) {
+		enum object_type type;
+		unsigned long size;
+
+		mmfile[i].size = 0;
+		mmfile[i].ptr = NULL;
+		if (active_nr <= pos)
+			break;
+		ce = active_cache[pos++];
+		if (ce_namelen(ce) != len || memcmp(ce->name, path, len)
+		    || ce_stage(ce) != i + 1)
+			break;
+		mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
+		mmfile[i].size = size;
+	}
+	for (i = 0; i < 3; i++) {
+		if (!mmfile[i].ptr && !mmfile[i].size)
+			mmfile[i].ptr = xstrdup("");
+	}
+	/*
+	 * NEEDSWORK: handle conflicts from merges with
+	 * merge.renormalize set, too
+	 */
+	ll_merge(&result, path, &mmfile[0], NULL,
+		 &mmfile[1], "ours",
+		 &mmfile[2], "theirs", NULL);
+	for (i = 0; i < 3; i++)
+		free(mmfile[i].ptr);
+
+	memset(&io, 0, sizeof(io));
+	io.io.getline = rerere_mem_getline;
+	if (output)
+		io.io.output = fopen(output, "w");
+	else
+		io.io.output = NULL;
+	strbuf_init(&io.input, 0);
+	strbuf_attach(&io.input, result.ptr, result.size, result.size);
+
+	hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
+	strbuf_release(&io.input);
+	if (io.io.output)
+		fclose(io.io.output);
+	return hunk_no;
+}
+
+static int check_one_conflict(int i, int *type)
+{
+	struct cache_entry *e = active_cache[i];
+
+	if (!ce_stage(e)) {
+		*type = RESOLVED;
+		return i + 1;
+	}
+
+	*type = PUNTED;
+	if (ce_stage(e) == 1) {
+		if (active_nr <= ++i)
+			return i + 1;
+	}
+
+	/* Only handle regular files with both stages #2 and #3 */
+	if (i + 1 < active_nr) {
 		struct cache_entry *e2 = active_cache[i];
-		struct cache_entry *e3 = active_cache[i+1];
+		struct cache_entry *e3 = active_cache[i + 1];
 		if (ce_stage(e2) == 2 &&
 		    ce_stage(e3) == 3 &&
-		    ce_same_name(e2, e3) &&
+		    ce_same_name(e, e3) &&
 		    S_ISREG(e2->ce_mode) &&
-		    S_ISREG(e3->ce_mode)) {
-			string_list_insert((const char *)e2->name, conflict);
-			i++; /* skip over both #2 and #3 */
+		    S_ISREG(e3->ce_mode))
+			*type = THREE_STAGED;
+	}
+
+	/* Skip the entries with the same name */
+	while (i < active_nr && ce_same_name(e, active_cache[i]))
+		i++;
+	return i;
+}
+
+static int find_conflict(struct string_list *conflict)
+{
+	int i;
+	if (read_cache() < 0)
+		return error("Could not read index");
+
+	for (i = 0; i < active_nr;) {
+		int conflict_type;
+		struct cache_entry *e = active_cache[i];
+		i = check_one_conflict(i, &conflict_type);
+		if (conflict_type == THREE_STAGED)
+			string_list_insert(conflict, (const char *)e->name);
+	}
+	return 0;
+}
+
+int rerere_remaining(struct string_list *merge_rr)
+{
+	int i;
+	if (read_cache() < 0)
+		return error("Could not read index");
+
+	for (i = 0; i < active_nr;) {
+		int conflict_type;
+		struct cache_entry *e = active_cache[i];
+		i = check_one_conflict(i, &conflict_type);
+		if (conflict_type == PUNTED)
+			string_list_insert(merge_rr, (const char *)e->name);
+		else if (conflict_type == RESOLVED) {
+			struct string_list_item *it;
+			it = string_list_lookup(merge_rr, (const char *)e->name);
+			if (it != NULL) {
+				free(it->util);
+				it->util = RERERE_RESOLVED;
+			}
 		}
 	}
 	return 0;
@@ -204,21 +432,27 @@ static int find_conflict(struct string_list *conflict)
 static int merge(const char *name, const char *path)
 {
 	int ret;
-	mmfile_t cur, base, other;
+	mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
 	mmbuffer_t result = {NULL, 0};
-	xpparam_t xpp = {XDF_NEED_MINIMAL};
 
 	if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
 		return 1;
 
 	if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
 			read_mmfile(&base, rerere_path(name, "preimage")) ||
-			read_mmfile(&other, rerere_path(name, "postimage")))
-		return 1;
-	ret = xdl_merge(&base, &cur, "", &other, "",
-			&xpp, XDL_MERGE_ZEALOUS, &result);
+			read_mmfile(&other, rerere_path(name, "postimage"))) {
+		ret = 1;
+		goto out;
+	}
+	ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
 	if (!ret) {
-		FILE *f = fopen(path, "w");
+		FILE *f;
+
+		if (utime(rerere_path(name, "postimage"), NULL) < 0)
+			warning("failed utime() on %s: %s",
+					rerere_path(name, "postimage"),
+					strerror(errno));
+		f = fopen(path, "w");
 		if (!f)
 			return error("Could not open %s: %s", path,
 				     strerror(errno));
@@ -229,6 +463,7 @@ static int merge(const char *name, const char *path)
 				     strerror(errno));
 	}
 
+out:
 	free(cur.ptr);
 	free(base.ptr);
 	free(other.ptr);
@@ -265,8 +500,8 @@ static int update_paths(struct string_list *update)
 
 static int do_plain_rerere(struct string_list *rr, int fd)
 {
-	struct string_list conflict = { NULL, 0, 0, 1 };
-	struct string_list update = { NULL, 0, 0, 1 };
+	struct string_list conflict = STRING_LIST_INIT_DUP;
+	struct string_list update = STRING_LIST_INIT_DUP;
 	int i;
 
 	find_conflict(&conflict);
@@ -288,8 +523,8 @@ static int do_plain_rerere(struct string_list *rr, int fd)
 			if (ret < 1)
 				continue;
 			hex = xstrdup(sha1_to_hex(sha1));
-			string_list_insert(path, rr)->util = hex;
-			if (mkdir(git_path("rr-cache/%s", hex), 0755))
+			string_list_insert(rr, path)->util = hex;
+			if (mkdir_in_gitdir(git_path("rr-cache/%s", hex)))
 				continue;
 			handle_file(path, NULL, rerere_path(hex, "preimage"));
 			fprintf(stderr, "Recorded preimage for '%s'\n", path);
@@ -309,13 +544,13 @@ static int do_plain_rerere(struct string_list *rr, int fd)
 
 		if (has_rerere_resolution(name)) {
 			if (!merge(name, path)) {
-				if (rerere_autoupdate)
-					string_list_insert(path, &update);
-				fprintf(stderr,
-					"%s '%s' using previous resolution.\n",
-					rerere_autoupdate
-					? "Staged" : "Resolved",
-					path);
+				const char *msg;
+				if (rerere_autoupdate) {
+					string_list_insert(&update, path);
+					msg = "Staged '%s' using previous resolution.\n";
+				} else
+					msg = "Resolved '%s' using previous resolution.\n";
+				fprintf(stderr, msg, path);
 				goto mark_resolved;
 			}
 		}
@@ -361,13 +596,12 @@ static int is_rerere_enabled(void)
 	if (rerere_enabled < 0)
 		return rr_cache_exists;
 
-	if (!rr_cache_exists &&
-	    (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
+	if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
 		die("Could not create directory %s", rr_cache);
 	return 1;
 }
 
-int setup_rerere(struct string_list *merge_rr)
+int setup_rerere(struct string_list *merge_rr, int flags)
 {
 	int fd;
 
@@ -375,6 +609,8 @@ int setup_rerere(struct string_list *merge_rr)
 	if (!is_rerere_enabled())
 		return -1;
 
+	if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
+		rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
 	merge_rr_path = git_pathdup("MERGE_RR");
 	fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
 				       LOCK_DIE_ON_ERROR);
@@ -382,13 +618,147 @@ int setup_rerere(struct string_list *merge_rr)
 	return fd;
 }
 
-int rerere(void)
+int rerere(int flags)
 {
-	struct string_list merge_rr = { NULL, 0, 0, 1 };
+	struct string_list merge_rr = STRING_LIST_INIT_DUP;
 	int fd;
 
-	fd = setup_rerere(&merge_rr);
+	fd = setup_rerere(&merge_rr, flags);
 	if (fd < 0)
 		return 0;
 	return do_plain_rerere(&merge_rr, fd);
 }
+
+static int rerere_forget_one_path(const char *path, struct string_list *rr)
+{
+	const char *filename;
+	char *hex;
+	unsigned char sha1[20];
+	int ret;
+
+	ret = handle_cache(path, sha1, NULL);
+	if (ret < 1)
+		return error("Could not parse conflict hunks in '%s'", path);
+	hex = xstrdup(sha1_to_hex(sha1));
+	filename = rerere_path(hex, "postimage");
+	if (unlink(filename))
+		return (errno == ENOENT
+			? error("no remembered resolution for %s", path)
+			: error("cannot unlink %s: %s", filename, strerror(errno)));
+
+	handle_cache(path, sha1, rerere_path(hex, "preimage"));
+	fprintf(stderr, "Updated preimage for '%s'\n", path);
+
+
+	string_list_insert(rr, path)->util = hex;
+	fprintf(stderr, "Forgot resolution for %s\n", path);
+	return 0;
+}
+
+int rerere_forget(const char **pathspec)
+{
+	int i, fd;
+	struct string_list conflict = STRING_LIST_INIT_DUP;
+	struct string_list merge_rr = STRING_LIST_INIT_DUP;
+
+	if (read_cache() < 0)
+		return error("Could not read index");
+
+	fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
+
+	unmerge_cache(pathspec);
+	find_conflict(&conflict);
+	for (i = 0; i < conflict.nr; i++) {
+		struct string_list_item *it = &conflict.items[i];
+		if (!match_pathspec(pathspec, it->string, strlen(it->string),
+				    0, NULL))
+			continue;
+		rerere_forget_one_path(it->string, &merge_rr);
+	}
+	return write_rr(&merge_rr, fd);
+}
+
+static time_t rerere_created_at(const char *name)
+{
+	struct stat st;
+	return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
+}
+
+static time_t rerere_last_used_at(const char *name)
+{
+	struct stat st;
+	return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
+}
+
+static void unlink_rr_item(const char *name)
+{
+	unlink(rerere_path(name, "thisimage"));
+	unlink(rerere_path(name, "preimage"));
+	unlink(rerere_path(name, "postimage"));
+	rmdir(git_path("rr-cache/%s", name));
+}
+
+struct rerere_gc_config_cb {
+	int cutoff_noresolve;
+	int cutoff_resolve;
+};
+
+static int git_rerere_gc_config(const char *var, const char *value, void *cb)
+{
+	struct rerere_gc_config_cb *cf = cb;
+
+	if (!strcmp(var, "gc.rerereresolved"))
+		cf->cutoff_resolve = git_config_int(var, value);
+	else if (!strcmp(var, "gc.rerereunresolved"))
+		cf->cutoff_noresolve = git_config_int(var, value);
+	else
+		return git_default_config(var, value, cb);
+	return 0;
+}
+
+void rerere_gc(struct string_list *rr)
+{
+	struct string_list to_remove = STRING_LIST_INIT_DUP;
+	DIR *dir;
+	struct dirent *e;
+	int i, cutoff;
+	time_t now = time(NULL), then;
+	struct rerere_gc_config_cb cf = { 15, 60 };
+
+	git_config(git_rerere_gc_config, &cf);
+	dir = opendir(git_path("rr-cache"));
+	if (!dir)
+		die_errno("unable to open rr-cache directory");
+	while ((e = readdir(dir))) {
+		if (is_dot_or_dotdot(e->d_name))
+			continue;
+
+		then = rerere_last_used_at(e->d_name);
+		if (then) {
+			cutoff = cf.cutoff_resolve;
+		} else {
+			then = rerere_created_at(e->d_name);
+			if (!then)
+				continue;
+			cutoff = cf.cutoff_noresolve;
+		}
+		if (then < now - cutoff * 86400)
+			string_list_append(&to_remove, e->d_name);
+	}
+	closedir(dir);
+	for (i = 0; i < to_remove.nr; i++)
+		unlink_rr_item(to_remove.items[i].string);
+	string_list_clear(&to_remove, 0);
+}
+
+void rerere_clear(struct string_list *merge_rr)
+{
+	int i;
+
+	for (i = 0; i < merge_rr->nr; i++) {
+		const char *name = (const char *)merge_rr->items[i].util;
+		if (!has_rerere_resolution(name))
+			unlink_rr_item(name);
+	}
+	unlink_or_warn(git_path("MERGE_RR"));
+}