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-rw-r--r--Makefile2
-rw-r--r--builtin-checkout.c6
-rw-r--r--builtin-ls-files.c43
-rw-r--r--builtin-merge.c8
-rw-r--r--builtin-read-tree.c2
-rw-r--r--builtin-rerere.c3
-rw-r--r--builtin-update-index.c18
-rw-r--r--cache.h4
-rw-r--r--read-cache.c18
-rw-r--r--rerere.c259
-rw-r--r--rerere.h1
-rw-r--r--resolve-undo.c176
-rw-r--r--resolve-undo.h16
-rwxr-xr-xt/t2030-unresolve-info.sh143
14 files changed, 652 insertions, 47 deletions
diff --git a/Makefile b/Makefile
index cf0723ea12..ad890ec925 100644
--- a/Makefile
+++ b/Makefile
@@ -497,6 +497,7 @@ LIB_H += reflog-walk.h
LIB_H += refs.h
LIB_H += remote.h
LIB_H += rerere.h
+LIB_H += resolve-undo.h
LIB_H += revision.h
LIB_H += run-command.h
LIB_H += sha1-lookup.h
@@ -592,6 +593,7 @@ LIB_OBJS += refs.o
LIB_OBJS += remote.o
LIB_OBJS += replace_object.o
LIB_OBJS += rerere.o
+LIB_OBJS += resolve-undo.o
LIB_OBJS += revision.o
LIB_OBJS += run-command.o
LIB_OBJS += server-info.o
diff --git a/builtin-checkout.c b/builtin-checkout.c
index e44e238c39..d0b1a728cb 100644
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -17,6 +17,7 @@
#include "blob.h"
#include "xdiff-interface.h"
#include "ll-merge.h"
+#include "resolve-undo.h"
static const char * const checkout_usage[] = {
"git checkout [options] <branch>",
@@ -234,6 +235,10 @@ static int checkout_paths(struct tree *source_tree, const char **pathspec,
if (report_path_error(ps_matched, pathspec, 0))
return 1;
+ /* "checkout -m path" to recreate conflicted state */
+ if (opts->merge)
+ unmerge_cache(pathspec);
+
/* Any unmerged paths? */
for (pos = 0; pos < active_nr; pos++) {
struct cache_entry *ce = active_cache[pos];
@@ -370,6 +375,7 @@ static int merge_working_tree(struct checkout_opts *opts,
if (read_cache_preload(NULL) < 0)
return error("corrupt index file");
+ resolve_undo_clear();
if (opts->force) {
ret = reset_tree(new->commit->tree, opts, 1);
if (ret)
diff --git a/builtin-ls-files.c b/builtin-ls-files.c
index 738215768e..b065061392 100644
--- a/builtin-ls-files.c
+++ b/builtin-ls-files.c
@@ -11,6 +11,8 @@
#include "builtin.h"
#include "tree.h"
#include "parse-options.h"
+#include "resolve-undo.h"
+#include "string-list.h"
static int abbrev;
static int show_deleted;
@@ -18,6 +20,7 @@ static int show_cached;
static int show_others;
static int show_stage;
static int show_unmerged;
+static int show_resolve_undo;
static int show_modified;
static int show_killed;
static int show_valid_bit;
@@ -38,6 +41,7 @@ static const char *tag_other = "";
static const char *tag_killed = "";
static const char *tag_modified = "";
static const char *tag_skip_worktree = "";
+static const char *tag_resolve_undo = "";
static void show_dir_entry(const char *tag, struct dir_entry *ent)
{
@@ -156,6 +160,38 @@ static void show_ce_entry(const char *tag, struct cache_entry *ce)
write_name_quoted(ce->name + offset, stdout, line_terminator);
}
+static int show_one_ru(struct string_list_item *item, void *cbdata)
+{
+ int offset = prefix_offset;
+ const char *path = item->string;
+ struct resolve_undo_info *ui = item->util;
+ int i, len;
+
+ len = strlen(path);
+ if (len < prefix_len)
+ return 0; /* outside of the prefix */
+ if (!match_pathspec(pathspec, path, len, prefix_len, ps_matched))
+ return 0; /* uninterested */
+ for (i = 0; i < 3; i++) {
+ if (!ui->mode[i])
+ continue;
+ printf("%s%06o %s %d\t", tag_resolve_undo, ui->mode[i],
+ abbrev
+ ? find_unique_abbrev(ui->sha1[i], abbrev)
+ : sha1_to_hex(ui->sha1[i]),
+ i + 1);
+ write_name_quoted(path + offset, stdout, line_terminator);
+ }
+ return 0;
+}
+
+static void show_ru_info(const char *prefix)
+{
+ if (!the_index.resolve_undo)
+ return;
+ for_each_string_list(show_one_ru, the_index.resolve_undo, NULL);
+}
+
static void show_files(struct dir_struct *dir, const char *prefix)
{
int i;
@@ -458,6 +494,8 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
DIR_HIDE_EMPTY_DIRECTORIES),
OPT_BOOLEAN('u', "unmerged", &show_unmerged,
"show unmerged files in the output"),
+ OPT_BOOLEAN(0, "resolve-undo", &show_resolve_undo,
+ "show resolve-undo information"),
{ OPTION_CALLBACK, 'x', "exclude", &dir.exclude_list[EXC_CMDL], "pattern",
"skip files matching pattern",
0, option_parse_exclude },
@@ -498,6 +536,7 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
tag_other = "? ";
tag_killed = "K ";
tag_skip_worktree = "S ";
+ tag_resolve_undo = "U ";
}
if (show_modified || show_others || show_deleted || (dir.flags & DIR_SHOW_IGNORED) || show_killed)
require_work_tree = 1;
@@ -536,7 +575,7 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
/* With no flags, we default to showing the cached files */
if (!(show_stage | show_deleted | show_others | show_unmerged |
- show_killed | show_modified))
+ show_killed | show_modified | show_resolve_undo))
show_cached = 1;
if (prefix)
@@ -551,6 +590,8 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
overlay_tree_on_cache(with_tree, prefix);
}
show_files(&dir, prefix);
+ if (show_resolve_undo)
+ show_ru_info(prefix);
if (ps_matched) {
int bad;
diff --git a/builtin-merge.c b/builtin-merge.c
index 6f1311414b..9f60ffa2cd 100644
--- a/builtin-merge.c
+++ b/builtin-merge.c
@@ -24,6 +24,7 @@
#include "rerere.h"
#include "help.h"
#include "merge-recursive.h"
+#include "resolve-undo.h"
#define DEFAULT_TWOHEAD (1<<0)
#define DEFAULT_OCTOPUS (1<<1)
@@ -606,6 +607,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
discard_cache();
if (read_cache() < 0)
die("failed to read the cache");
+ resolve_undo_clear();
return ret;
}
}
@@ -620,11 +622,10 @@ static void count_diff_files(struct diff_queue_struct *q,
static int count_unmerged_entries(void)
{
- const struct index_state *state = &the_index;
int i, ret = 0;
- for (i = 0; i < state->cache_nr; i++)
- if (ce_stage(state->cache[i]))
+ for (i = 0; i < active_nr; i++)
+ if (ce_stage(active_cache[i]))
ret++;
return ret;
@@ -864,6 +865,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
die("You have not concluded your merge (MERGE_HEAD exists).");
}
+ resolve_undo_clear();
/*
* Check if we are _not_ on a detached HEAD, i.e. if there is a
* current branch.
diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 50413ca17d..5fda9905fc 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -13,6 +13,7 @@
#include "dir.h"
#include "builtin.h"
#include "parse-options.h"
+#include "resolve-undo.h"
static int nr_trees;
static struct tree *trees[MAX_UNPACK_TREES];
@@ -124,6 +125,7 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
die("You need to resolve your current index first");
stage = opts.merge = 1;
}
+ resolve_undo_clear();
for (i = 0; i < argc; i++) {
const char *arg = argv[i];
diff --git a/builtin-rerere.c b/builtin-rerere.c
index 5028138898..25f507a2f1 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -120,6 +120,9 @@ int cmd_rerere(int argc, const char **argv, const char *prefix)
if (argc < 2)
return rerere(flags);
+ if (!strcmp(argv[1], "forget"))
+ return rerere_forget(argv + 2);
+
fd = setup_rerere(&merge_rr, flags);
if (fd < 0)
return 0;
diff --git a/builtin-update-index.c b/builtin-update-index.c
index a64a752990..3ab214d24e 100644
--- a/builtin-update-index.c
+++ b/builtin-update-index.c
@@ -9,6 +9,7 @@
#include "tree-walk.h"
#include "builtin.h"
#include "refs.h"
+#include "resolve-undo.h"
/*
* Default to not allowing changes to the list of files. The
@@ -440,7 +441,18 @@ static int unresolve_one(const char *path)
/* See if there is such entry in the index. */
pos = cache_name_pos(path, namelen);
- if (pos < 0) {
+ if (0 <= pos) {
+ /* already merged */
+ pos = unmerge_cache_entry_at(pos);
+ if (pos < active_nr) {
+ struct cache_entry *ce = active_cache[pos];
+ if (ce_stage(ce) &&
+ ce_namelen(ce) == namelen &&
+ !memcmp(ce->name, path, namelen))
+ return 0;
+ }
+ /* no resolve-undo information; fall back */
+ } else {
/* If there isn't, either it is unmerged, or
* resolved as "removed" by mistake. We do not
* want to do anything in the former case.
@@ -719,6 +731,10 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
verbose = 1;
continue;
}
+ if (!strcmp(path, "--clear-resolve-undo")) {
+ resolve_undo_clear();
+ continue;
+ }
if (!strcmp(path, "-h") || !strcmp(path, "--help"))
usage(update_index_usage);
die("unknown option %s", path);
diff --git a/cache.h b/cache.h
index bebe1a891d..5abcb09fcf 100644
--- a/cache.h
+++ b/cache.h
@@ -288,6 +288,7 @@ static inline int ce_to_dtype(const struct cache_entry *ce)
struct index_state {
struct cache_entry **cache;
unsigned int cache_nr, cache_alloc, cache_changed;
+ struct string_list *resolve_undo;
struct cache_tree *cache_tree;
struct cache_time timestamp;
void *alloc;
@@ -342,6 +343,9 @@ static inline void remove_name_hash(struct cache_entry *ce)
#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
#define cache_name_exists(name, namelen, igncase) index_name_exists(&the_index, (name), (namelen), (igncase))
#define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen))
+#define resolve_undo_clear() resolve_undo_clear_index(&the_index)
+#define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
+#define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
#endif
enum object_type {
diff --git a/read-cache.c b/read-cache.c
index f4512967b8..edd995943d 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -14,6 +14,7 @@
#include "diffcore.h"
#include "revision.h"
#include "blob.h"
+#include "resolve-undo.h"
static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
@@ -28,6 +29,7 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int reall
#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
+#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUN" */
struct index_state the_index;
@@ -456,6 +458,7 @@ int remove_index_entry_at(struct index_state *istate, int pos)
{
struct cache_entry *ce = istate->cache[pos];
+ record_resolve_undo(istate, ce);
remove_name_hash(ce);
istate->cache_changed = 1;
istate->cache_nr--;
@@ -1183,6 +1186,9 @@ static int read_index_extension(struct index_state *istate,
case CACHE_EXT_TREE:
istate->cache_tree = cache_tree_read(data, sz);
break;
+ case CACHE_EXT_RESOLVE_UNDO:
+ istate->resolve_undo = resolve_undo_read(data, sz);
+ break;
default:
if (*ext < 'A' || 'Z' < *ext)
return error("index uses %.4s extension, which we do not understand",
@@ -1362,6 +1368,7 @@ int is_index_unborn(struct index_state *istate)
int discard_index(struct index_state *istate)
{
+ resolve_undo_clear_index(istate);
istate->cache_nr = 0;
istate->cache_changed = 0;
istate->timestamp.sec = 0;
@@ -1587,6 +1594,17 @@ int write_index(struct index_state *istate, int newfd)
if (err)
return -1;
}
+ if (istate->resolve_undo) {
+ struct strbuf sb = STRBUF_INIT;
+
+ resolve_undo_write(&sb, istate->resolve_undo);
+ err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
+ sb.len) < 0
+ || ce_write(&c, newfd, sb.buf, sb.len) < 0;
+ strbuf_release(&sb);
+ if (err)
+ return -1;
+ }
if (ce_flush(&c, newfd) || fstat(newfd, &st))
return -1;
diff --git a/rerere.c b/rerere.c
index e0ac5bcaed..70d0f7afff 100644
--- a/rerere.c
+++ b/rerere.c
@@ -3,6 +3,9 @@
#include "rerere.h"
#include "xdiff/xdiff.h"
#include "xdiff-interface.h"
+#include "dir.h"
+#include "resolve-undo.h"
+#include "ll-merge.h"
/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
static int rerere_enabled = -1;
@@ -83,61 +86,74 @@ 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_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 handle_path(unsigned char *sha1, struct rerere_io *io)
{
git_SHA_CTX ctx;
- char buf[1024];
int hunk_no = 0;
enum {
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 (!prefixcmp(buf.buf, "<<<<<<< ")) {
if (hunk != RR_CONTEXT)
goto bad;
hunk = RR_SIDE_1;
- } else if (!prefixcmp(buf, "|||||||") && isspace(buf[7])) {
+ } else if (!prefixcmp(buf.buf, "|||||||") && isspace(buf.buf[7])) {
if (hunk != RR_SIDE_1)
goto bad;
hunk = RR_ORIGINAL;
- } else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
+ } else if (!prefixcmp(buf.buf, "=======") && isspace(buf.buf[7])) {
if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
goto bad;
hunk = RR_SIDE_2;
- } else if (!prefixcmp(buf, ">>>>>>> ")) {
+ } else if (!prefixcmp(buf.buf, ">>>>>>> ")) {
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_putstr("<<<<<<<\n", io);
+ rerere_io_putmem(one.buf, one.len, io);
+ rerere_io_putstr("=======\n", io);
+ rerere_io_putmem(two.buf, two.len, io);
+ rerere_io_putstr(">>>>>>>\n", io);
if (sha1) {
git_SHA1_Update(&ctx, one.buf ? one.buf : "",
one.len + 1);
@@ -147,13 +163,13 @@ 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 */
@@ -161,23 +177,133 @@ 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;
+
+ 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);
+
+ 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;
+}
+
+struct rerere_io_mem {
+ struct rerere_io io;
+ struct strbuf input;
+};
+
+static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
+{
+ 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;
+
+ /*
+ * 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("");
+ }
+ ll_merge(&result, path, &mmfile[0],
+ &mmfile[1], "ours",
+ &mmfile[2], "theirs", 0);
+ 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);
+ strbuf_release(&io.input);
+ if (io.io.output)
+ fclose(io.io.output);
return hunk_no;
}
@@ -394,3 +520,52 @@ int rerere(int flags)
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(path, rr)->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 = { NULL, 0, 0, 1 };
+ struct string_list merge_rr = { NULL, 0, 0, 1 };
+
+ 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);
+}
diff --git a/rerere.h b/rerere.h
index 10a94a4ea1..eaa9004dcd 100644
--- a/rerere.h
+++ b/rerere.h
@@ -10,6 +10,7 @@ extern int setup_rerere(struct string_list *, int);
extern int rerere(int);
extern const char *rerere_path(const char *hex, const char *file);
extern int has_rerere_resolution(const char *hex);
+extern int rerere_forget(const char **);
#define OPT_RERERE_AUTOUPDATE(v) OPT_UYN(0, "rerere-autoupdate", (v), \
"update the index with reused conflict resolution if possible")
diff --git a/resolve-undo.c b/resolve-undo.c
new file mode 100644
index 0000000000..37d73cd949
--- /dev/null
+++ b/resolve-undo.c
@@ -0,0 +1,176 @@
+#include "cache.h"
+#include "dir.h"
+#include "resolve-undo.h"
+#include "string-list.h"
+
+/* The only error case is to run out of memory in string-list */
+void record_resolve_undo(struct index_state *istate, struct cache_entry *ce)
+{
+ struct string_list_item *lost;
+ struct resolve_undo_info *ui;
+ struct string_list *resolve_undo;
+ int stage = ce_stage(ce);
+
+ if (!stage)
+ return;
+
+ if (!istate->resolve_undo) {
+ resolve_undo = xcalloc(1, sizeof(*resolve_undo));
+ resolve_undo->strdup_strings = 1;
+ istate->resolve_undo = resolve_undo;
+ }
+ resolve_undo = istate->resolve_undo;
+ lost = string_list_insert(ce->name, resolve_undo);
+ if (!lost->util)
+ lost->util = xcalloc(1, sizeof(*ui));
+ ui = lost->util;
+ hashcpy(ui->sha1[stage - 1], ce->sha1);
+ ui->mode[stage - 1] = ce->ce_mode;
+}
+
+static int write_one(struct string_list_item *item, void *cbdata)
+{
+ struct strbuf *sb = cbdata;
+ struct resolve_undo_info *ui = item->util;
+ int i;
+
+ if (!ui)
+ return 0;
+ strbuf_addstr(sb, item->string);
+ strbuf_addch(sb, 0);
+ for (i = 0; i < 3; i++)
+ strbuf_addf(sb, "%o%c", ui->mode[i], 0);
+ for (i = 0; i < 3; i++) {
+ if (!ui->mode[i])
+ continue;
+ strbuf_add(sb, ui->sha1[i], 20);
+ }
+ return 0;
+}
+
+void resolve_undo_write(struct strbuf *sb, struct string_list *resolve_undo)
+{
+ for_each_string_list(write_one, resolve_undo, sb);
+}
+
+struct string_list *resolve_undo_read(void *data, unsigned long size)
+{
+ struct string_list *resolve_undo;
+ size_t len;
+ char *endptr;
+ int i;
+
+ resolve_undo = xcalloc(1, sizeof(*resolve_undo));
+ resolve_undo->strdup_strings = 1;
+
+ while (size) {
+ struct string_list_item *lost;
+ struct resolve_undo_info *ui;
+
+ len = strlen(data) + 1;
+ if (size <= len)
+ goto error;
+ lost = string_list_insert(data, resolve_undo);
+ if (!lost->util)
+ lost->util = xcalloc(1, sizeof(*ui));
+ ui = lost->util;
+ size -= len;
+ data += len;
+
+ for (i = 0; i < 3; i++) {
+ ui->mode[i] = strtoul(data, &endptr, 8);
+ if (!endptr || endptr == data || *endptr)
+ goto error;
+ len = (endptr + 1) - (char*)data;
+ if (size <= len)
+ goto error;
+ size -= len;
+ data += len;
+ }
+
+ for (i = 0; i < 3; i++) {
+ if (!ui->mode[i])
+ continue;
+ if (size < 20)
+ goto error;
+ hashcpy(ui->sha1[i], data);
+ size -= 20;
+ data += 20;
+ }
+ }
+ return resolve_undo;
+
+error:
+ string_list_clear(resolve_undo, 1);
+ error("Index records invalid resolve-undo information");
+ return NULL;
+}
+
+void resolve_undo_clear_index(struct index_state *istate)
+{
+ struct string_list *resolve_undo = istate->resolve_undo;
+ if (!resolve_undo)
+ return;
+ string_list_clear(resolve_undo, 1);
+ free(resolve_undo);
+ istate->resolve_undo = NULL;
+ istate->cache_changed = 1;
+}
+
+int unmerge_index_entry_at(struct index_state *istate, int pos)
+{
+ struct cache_entry *ce;
+ struct string_list_item *item;
+ struct resolve_undo_info *ru;
+ int i, err = 0;
+
+ if (!istate->resolve_undo)
+ return pos;
+
+ ce = istate->cache[pos];
+ if (ce_stage(ce)) {
+ /* already unmerged */
+ while ((pos < istate->cache_nr) &&
+ ! strcmp(istate->cache[pos]->name, ce->name))
+ pos++;
+ return pos - 1; /* return the last entry processed */
+ }
+ item = string_list_lookup(ce->name, istate->resolve_undo);
+ if (!item)
+ return pos;
+ ru = item->util;
+ if (!ru)
+ return pos;
+ remove_index_entry_at(istate, pos);
+ for (i = 0; i < 3; i++) {
+ struct cache_entry *nce;
+ if (!ru->mode[i])
+ continue;
+ nce = make_cache_entry(ru->mode[i], ru->sha1[i],
+ ce->name, i + 1, 0);
+ if (add_index_entry(istate, nce, ADD_CACHE_OK_TO_ADD)) {
+ err = 1;
+ error("cannot unmerge '%s'", ce->name);
+ }
+ }
+ if (err)
+ return pos;
+ free(ru);
+ item->util = NULL;
+ return unmerge_index_entry_at(istate, pos);
+}
+
+void unmerge_index(struct index_state *istate, const char **pathspec)
+{
+ int i;
+
+ if (!istate->resolve_undo)
+ return;
+
+ for (i = 0; i < istate->cache_nr; i++) {
+ struct cache_entry *ce = istate->cache[i];
+ if (!match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL))
+ continue;
+ i = unmerge_index_entry_at(istate, i);
+ }
+}
diff --git a/resolve-undo.h b/resolve-undo.h
new file mode 100644
index 0000000000..e4e5c1b1ad
--- /dev/null
+++ b/resolve-undo.h
@@ -0,0 +1,16 @@
+#ifndef RESOLVE_UNDO_H
+#define RESOLVE_UNDO_H
+
+struct resolve_undo_info {
+ unsigned int mode[3];
+ unsigned char sha1[3][20];
+};
+
+extern void record_resolve_undo(struct index_state *, struct cache_entry *);
+extern void resolve_undo_write(struct strbuf *, struct string_list *);
+extern struct string_list *resolve_undo_read(void *, unsigned long);
+extern void resolve_undo_clear_index(struct index_state *);
+extern int unmerge_index_entry_at(struct index_state *, int);
+extern void unmerge_index(struct index_state *, const char **);
+
+#endif
diff --git a/t/t2030-unresolve-info.sh b/t/t2030-unresolve-info.sh
new file mode 100755
index 0000000000..a38bd6df84
--- /dev/null
+++ b/t/t2030-unresolve-info.sh
@@ -0,0 +1,143 @@
+#!/bin/sh
+
+test_description='undoing resolution'
+
+. ./test-lib.sh
+
+check_resolve_undo () {
+ msg=$1
+ shift
+ while case $# in
+ 0) break ;;
+ 1|2|3) die "Bug in check-resolve-undo test" ;;
+ esac
+ do
+ path=$1
+ shift
+ for stage in 1 2 3
+ do
+ sha1=$1
+ shift
+ case "$sha1" in
+ '') continue ;;
+ esac
+ sha1=$(git rev-parse --verify "$sha1")
+ printf "100644 %s %s\t%s\n" $sha1 $stage $path
+ done
+ done >"$msg.expect" &&
+ git ls-files --resolve-undo >"$msg.actual" &&
+ test_cmp "$msg.expect" "$msg.actual"
+}
+
+prime_resolve_undo () {
+ git reset --hard &&
+ git checkout second^0 &&
+ test_tick &&
+ test_must_fail git merge third^0 &&
+ echo merge does not leave anything &&
+ check_resolve_undo empty &&
+ echo different >file &&
+ git add file &&
+ echo resolving records &&
+ check_resolve_undo recorded file initial:file second:file third:file
+}
+
+test_expect_success setup '
+ test_commit initial file first &&
+ git branch side &&
+ git branch another &&
+ test_commit second file second &&
+ git checkout side &&
+ test_commit third file third &&
+ git checkout another &&
+ test_commit fourth file fourth &&
+ git checkout master
+'
+
+test_expect_success 'add records switch clears' '
+ prime_resolve_undo &&
+ test_tick &&
+ git commit -m merged &&
+ echo committing keeps &&
+ check_resolve_undo kept file initial:file second:file third:file &&
+ git checkout second^0 &&
+ echo switching clears &&
+ check_resolve_undo cleared
+'
+
+test_expect_success 'rm records reset clears' '
+ prime_resolve_undo &&
+ test_tick &&
+ git commit -m merged &&
+ echo committing keeps &&
+ check_resolve_undo kept file initial:file second:file third:file &&
+
+ echo merge clears upfront &&
+ test_must_fail git merge fourth^0 &&
+ check_resolve_undo nuked &&
+
+ git rm -f file &&
+ echo resolving records &&
+ check_resolve_undo recorded file initial:file HEAD:file fourth:file &&
+
+ git reset --hard &&
+ echo resetting discards &&
+ check_resolve_undo discarded
+'
+
+test_expect_success 'plumbing clears' '
+ prime_resolve_undo &&
+ test_tick &&
+ git commit -m merged &&
+ echo committing keeps &&
+ check_resolve_undo kept file initial:file second:file third:file &&
+
+ echo plumbing clear &&
+ git update-index --clear-resolve-undo &&
+ check_resolve_undo cleared
+'
+
+test_expect_success 'add records checkout -m undoes' '
+ prime_resolve_undo &&
+ git diff HEAD &&
+ git checkout --conflict=merge file &&
+ echo checkout used the record and removed it &&
+ check_resolve_undo removed &&
+ echo the index and the work tree is unmerged again &&
+ git diff >actual &&
+ grep "^++<<<<<<<" actual
+'
+
+test_expect_success 'unmerge with plumbing' '
+ prime_resolve_undo &&
+ git update-index --unresolve file &&
+ git ls-files -u >actual &&
+ test $(wc -l <actual) = 3
+'
+
+test_expect_success 'rerere and rerere --forget' '
+ mkdir .git/rr-cache &&
+ prime_resolve_undo &&
+ echo record the resolution &&
+ git rerere &&
+ rerere_id=$(cd .git/rr-cache && echo */postimage) &&
+ rerere_id=${rerere_id%/postimage} &&
+ test -f .git/rr-cache/$rerere_id/postimage &&
+ git checkout -m file &&
+ echo resurrect the conflict &&
+ grep "^=======" file &&
+ echo reresolve the conflict &&
+ git rerere &&
+ test "z$(cat file)" = zdifferent &&
+ echo register the resolution again &&
+ git add file &&
+ check_resolve_undo kept file initial:file second:file third:file &&
+ test -z "$(git ls-files -u)" &&
+ git rerere forget file &&
+ ! test -f .git/rr-cache/$rerere_id/postimage &&
+ tr "\0" "\n" <.git/MERGE_RR >actual &&
+ echo "$rerere_id file" >expect &&
+ test_cmp expect actual
+'
+
+test_done