[PATCH 2/9] resolve-undo: record resolved conflicts in a new index extension section
When resolving a conflict using "git add" to create a stage #0 entry, or "git rm" to remove entries at higher stages, remove_index_entry_at() function is eventually called to remove unmerged (i.e. higher stage) entries from the index. Introduce a "resolve_undo_info" structure and keep track of the removed cache entries, and save it in a new index extension section in the index_state.
Operations like "read-tree -m", "merge", "checkout [-m] <branch>" and "reset" are signs that recorded information in the index is no longer necessary. The data is removed from the index extension when operations start; they may leave conflicted entries in the index, and later user actions like "git add" will record their conflicted states afresh.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Makefile | 2 +
builtin-checkout.c | 2 +
builtin-merge.c | 4 +-
builtin-read-tree.c | 2 +
cache.h | 2 +
read-cache.c | 18 ++++++++
resolve-undo.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++
resolve-undo.h | 14 ++++++
8 files changed, 160 insertions(+), 1 deletions(-)
create mode 100644 resolve-undo.c
create mode 100644 resolve-undo.h
Show changes to 8 files +160 −1
Makefile, builtin-checkout.c, builtin-merge.c, builtin-read-tree.c, cache.h, read-cache.c, resolve-undo.c, resolve-undo.h
diff --git a/Makefile b/Makefile
index 4a1e5bc..762898a 100644
--- a/Makefile
+++ b/Makefile
@@ -483,6 +483,7 @@ 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
@@ -578,6 +579,7 @@ 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 64f3a11..a0fe7a4 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>",
@@ -370,6 +371,7 @@ 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-merge.c b/builtin-merge.c
index 6cb804b..6bc2f7a 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)
@@ -604,6 +605,7 @@ 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;
}
}
@@ -851,7 +853,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
if (read_cache_unmerged())
die("You are in the middle of a conflicted merge."
" (index unmerged)");
-
+ 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 2a3a32c..7d378b7 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];
@@ -122,6 +123,7 @@ 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/cache.h b/cache.h
index bf468e5..310d9e6 100644
--- a/cache.h
+++ b/cache.h
@@ -282,6 +282,7 @@ 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;
@@ -336,6 +337,7 @@ 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)
#endif
enum object_type {
diff --git a/read-cache.c b/read-cache.c
index 1bbaf1c..9e0fb04 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"
/* Index extensions.
*
@@ -26,6 +27,7 @@
#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;
@@ -449,6 +451,7 @@ 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--;
@@ -1170,6 +1173,9 @@ 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",
@@ -1349,6 +1355,7 @@ 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;
@@ -1574,6 +1581,17 @@ 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/resolve-undo.c b/resolve-undo.c
new file mode 100644
index 0000000..86e8547
--- /dev/null
+++ b/resolve-undo.c
@@ -0,0 +1,117 @@
+#include "cache.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;
+}
diff --git a/resolve-undo.h b/resolve-undo.h
new file mode 100644
index 0000000..74194d0
--- /dev/null
+++ b/resolve-undo.h
@@ -0,0 +1,14 @@
+#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 *);
+
+#endif
Junio C Hamano