Merge branch 'js/merge-rr'

* js/merge-rr:
  Move MERGE_RR from .git/rr-cache/ into .git/

Conflicts:
	builtin-rerere.c

diff --cc rerere.c
index eec2b501072a44f34093cc48acd2c2d5020f04b1,0000000000000000000000000000000000000000..12589215e867bff37d5f2848083e8f138331e8ee
mode 100644,000000..100644
--- 1/rerere.c
--- /dev/null
+++ b/rerere.c
@@@ -1,360 -1,0 +1,360 @@@
-       merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
 +#include "cache.h"
 +#include "path-list.h"
 +#include "rerere.h"
 +#include "xdiff/xdiff.h"
 +#include "xdiff-interface.h"
 +
 +/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
 +static int rerere_enabled = -1;
 +
 +/* automatically update cleanly resolved paths to the index */
 +static int rerere_autoupdate;
 +
 +static char *merge_rr_path;
 +
 +static const char *rr_path(const char *name, const char *file)
 +{
 +      return git_path("rr-cache/%s/%s", name, file);
 +}
 +
 +static int has_resolution(const char *name)
 +{
 +      struct stat st;
 +      return !stat(rr_path(name, "postimage"), &st);
 +}
 +
 +static void read_rr(struct path_list *rr)
 +{
 +      unsigned char sha1[20];
 +      char buf[PATH_MAX];
 +      FILE *in = fopen(merge_rr_path, "r");
 +      if (!in)
 +              return;
 +      while (fread(buf, 40, 1, in) == 1) {
 +              int i;
 +              char *name;
 +              if (get_sha1_hex(buf, sha1))
 +                      die("corrupt MERGE_RR");
 +              buf[40] = '\0';
 +              name = xstrdup(buf);
 +              if (fgetc(in) != '\t')
 +                      die("corrupt MERGE_RR");
 +              for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
 +                      ; /* do nothing */
 +              if (i == sizeof(buf))
 +                      die("filename too long");
 +              path_list_insert(buf, rr)->util = name;
 +      }
 +      fclose(in);
 +}
 +
 +static struct lock_file write_lock;
 +
 +static int write_rr(struct path_list *rr, int out_fd)
 +{
 +      int i;
 +      for (i = 0; i < rr->nr; i++) {
 +              const char *path;
 +              int length;
 +              if (!rr->items[i].util)
 +                      continue;
 +              path = rr->items[i].path;
 +              length = strlen(path) + 1;
 +              if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
 +                  write_in_full(out_fd, "\t", 1) != 1 ||
 +                  write_in_full(out_fd, path, length) != length)
 +                      die("unable to write rerere record");
 +      }
 +      if (commit_lock_file(&write_lock) != 0)
 +              die("unable to write rerere record");
 +      return 0;
 +}
 +
 +static int handle_file(const char *path,
 +       unsigned char *sha1, const char *output)
 +{
 +      SHA_CTX ctx;
 +      char buf[1024];
 +      int hunk = 0, hunk_no = 0;
 +      struct strbuf one, two;
 +      FILE *f = fopen(path, "r");
 +      FILE *out = NULL;
 +
 +      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);
 +              }
 +      }
 +
 +      if (sha1)
 +              SHA1_Init(&ctx);
 +
 +      strbuf_init(&one, 0);
 +      strbuf_init(&two,  0);
 +      while (fgets(buf, sizeof(buf), f)) {
 +              if (!prefixcmp(buf, "<<<<<<< ")) {
 +                      if (hunk)
 +                              goto bad;
 +                      hunk = 1;
 +              } else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
 +                      if (hunk != 1)
 +                              goto bad;
 +                      hunk = 2;
 +              } else if (!prefixcmp(buf, ">>>>>>> ")) {
 +                      if (hunk != 2)
 +                              goto bad;
 +                      if (strbuf_cmp(&one, &two) > 0)
 +                              strbuf_swap(&one, &two);
 +                      hunk_no++;
 +                      hunk = 0;
 +                      if (out) {
 +                              fputs("<<<<<<<\n", out);
 +                              fwrite(one.buf, one.len, 1, out);
 +                              fputs("=======\n", out);
 +                              fwrite(two.buf, two.len, 1, out);
 +                              fputs(">>>>>>>\n", out);
 +                      }
 +                      if (sha1) {
 +                              SHA1_Update(&ctx, one.buf ? one.buf : "",
 +                                          one.len + 1);
 +                              SHA1_Update(&ctx, two.buf ? two.buf : "",
 +                                          two.len + 1);
 +                      }
 +                      strbuf_reset(&one);
 +                      strbuf_reset(&two);
 +              } else if (hunk == 1)
 +                      strbuf_addstr(&one, buf);
 +              else if (hunk == 2)
 +                      strbuf_addstr(&two, buf);
 +              else if (out)
 +                      fputs(buf, out);
 +              continue;
 +      bad:
 +              hunk = 99; /* force error exit */
 +              break;
 +      }
 +      strbuf_release(&one);
 +      strbuf_release(&two);
 +
 +      fclose(f);
 +      if (out)
 +              fclose(out);
 +      if (sha1)
 +              SHA1_Final(sha1, &ctx);
 +      if (hunk) {
 +              if (output)
 +                      unlink(output);
 +              return error("Could not parse conflict hunks in %s", path);
 +      }
 +      return hunk_no;
 +}
 +
 +static int find_conflict(struct path_list *conflict)
 +{
 +      int i;
 +      if (read_cache() < 0)
 +              return error("Could not read index");
 +      for (i = 0; i+1 < active_nr; i++) {
 +              struct cache_entry *e2 = active_cache[i];
 +              struct cache_entry *e3 = active_cache[i+1];
 +              if (ce_stage(e2) == 2 &&
 +                  ce_stage(e3) == 3 &&
 +                  ce_same_name(e2, e3) &&
 +                  S_ISREG(e2->ce_mode) &&
 +                  S_ISREG(e3->ce_mode)) {
 +                      path_list_insert((const char *)e2->name, conflict);
 +                      i++; /* skip over both #2 and #3 */
 +              }
 +      }
 +      return 0;
 +}
 +
 +static int merge(const char *name, const char *path)
 +{
 +      int ret;
 +      mmfile_t cur, base, other;
 +      mmbuffer_t result = {NULL, 0};
 +      xpparam_t xpp = {XDF_NEED_MINIMAL};
 +
 +      if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
 +              return 1;
 +
 +      if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
 +                      read_mmfile(&base, rr_path(name, "preimage")) ||
 +                      read_mmfile(&other, rr_path(name, "postimage")))
 +              return 1;
 +      ret = xdl_merge(&base, &cur, "", &other, "",
 +                      &xpp, XDL_MERGE_ZEALOUS, &result);
 +      if (!ret) {
 +              FILE *f = fopen(path, "w");
 +              if (!f)
 +                      return error("Could not write to %s", path);
 +              fwrite(result.ptr, result.size, 1, f);
 +              fclose(f);
 +      }
 +
 +      free(cur.ptr);
 +      free(base.ptr);
 +      free(other.ptr);
 +      free(result.ptr);
 +
 +      return ret;
 +}
 +
 +static struct lock_file index_lock;
 +
 +static int update_paths(struct path_list *update)
 +{
 +      int i;
 +      int fd = hold_locked_index(&index_lock, 0);
 +      int status = 0;
 +
 +      if (fd < 0)
 +              return -1;
 +
 +      for (i = 0; i < update->nr; i++) {
 +              struct path_list_item *item = &update->items[i];
 +              if (add_file_to_cache(item->path, ADD_CACHE_IGNORE_ERRORS))
 +                      status = -1;
 +      }
 +
 +      if (!status && active_cache_changed) {
 +              if (write_cache(fd, active_cache, active_nr) ||
 +                  commit_locked_index(&index_lock))
 +                      die("Unable to write new index file");
 +      } else if (fd >= 0)
 +              rollback_lock_file(&index_lock);
 +      return status;
 +}
 +
 +static int do_plain_rerere(struct path_list *rr, int fd)
 +{
 +      struct path_list conflict = { NULL, 0, 0, 1 };
 +      struct path_list update = { NULL, 0, 0, 1 };
 +      int i;
 +
 +      find_conflict(&conflict);
 +
 +      /*
 +       * MERGE_RR records paths with conflicts immediately after merge
 +       * failed.  Some of the conflicted paths might have been hand resolved
 +       * in the working tree since then, but the initial run would catch all
 +       * and register their preimages.
 +       */
 +
 +      for (i = 0; i < conflict.nr; i++) {
 +              const char *path = conflict.items[i].path;
 +              if (!path_list_has_path(rr, path)) {
 +                      unsigned char sha1[20];
 +                      char *hex;
 +                      int ret;
 +                      ret = handle_file(path, sha1, NULL);
 +                      if (ret < 1)
 +                              continue;
 +                      hex = xstrdup(sha1_to_hex(sha1));
 +                      path_list_insert(path, rr)->util = hex;
 +                      if (mkdir(git_path("rr-cache/%s", hex), 0755))
 +                              continue;;
 +                      handle_file(path, NULL, rr_path(hex, "preimage"));
 +                      fprintf(stderr, "Recorded preimage for '%s'\n", path);
 +              }
 +      }
 +
 +      /*
 +       * Now some of the paths that had conflicts earlier might have been
 +       * hand resolved.  Others may be similar to a conflict already that
 +       * was resolved before.
 +       */
 +
 +      for (i = 0; i < rr->nr; i++) {
 +              int ret;
 +              const char *path = rr->items[i].path;
 +              const char *name = (const char *)rr->items[i].util;
 +
 +              if (has_resolution(name)) {
 +                      if (!merge(name, path)) {
 +                              fprintf(stderr, "Resolved '%s' using "
 +                                              "previous resolution.\n", path);
 +                              if (rerere_autoupdate)
 +                                      path_list_insert(path, &update);
 +                              goto mark_resolved;
 +                      }
 +              }
 +
 +              /* Let's see if we have resolved it. */
 +              ret = handle_file(path, NULL, NULL);
 +              if (ret)
 +                      continue;
 +
 +              fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 +              copy_file(rr_path(name, "postimage"), path, 0666);
 +      mark_resolved:
 +              rr->items[i].util = NULL;
 +      }
 +
 +      if (update.nr)
 +              update_paths(&update);
 +
 +      return write_rr(rr, fd);
 +}
 +
 +static int git_rerere_config(const char *var, const char *value, void *cb)
 +{
 +      if (!strcmp(var, "rerere.enabled"))
 +              rerere_enabled = git_config_bool(var, value);
 +      else if (!strcmp(var, "rerere.autoupdate"))
 +              rerere_autoupdate = git_config_bool(var, value);
 +      else
 +              return git_default_config(var, value, cb);
 +      return 0;
 +}
 +
 +static int is_rerere_enabled(void)
 +{
 +      struct stat st;
 +      const char *rr_cache;
 +      int rr_cache_exists;
 +
 +      if (!rerere_enabled)
 +              return 0;
 +
 +      rr_cache = git_path("rr-cache");
 +      rr_cache_exists = !stat(rr_cache, &st) && S_ISDIR(st.st_mode);
 +      if (rerere_enabled < 0)
 +              return rr_cache_exists;
 +
 +      if (!rr_cache_exists &&
 +          (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
 +              die("Could not create directory %s", rr_cache);
 +      return 1;
 +}
 +
 +int setup_rerere(struct path_list *merge_rr)
 +{
 +      int fd;
 +
 +      git_config(git_rerere_config, NULL);
 +      if (!is_rerere_enabled())
 +              return -1;
 +
++      merge_rr_path = xstrdup(git_path("MERGE_RR"));
 +      fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
 +      read_rr(merge_rr);
 +      return fd;
 +}
 +
 +int rerere(void)
 +{
 +      struct path_list merge_rr = { NULL, 0, 0, 1 };
 +      int fd;
 +
 +      fd = setup_rerere(&merge_rr);
 +      if (fd < 0)
 +              return 0;
 +      return do_plain_rerere(&merge_rr, fd);
 +}