merge-base finds one of the best common ancestors of a pair of commits. In particular, it finds one of the ones which is fewest commits away from the further of the heads.
Signed-Off-By: Daniel Barkalow <[EMAIL PROTECTED]> Index: Makefile =================================================================== --- 37a0b01b85c2999243674d48bfc71cdba0e5518e/Makefile (mode:100644 sha1:346e3850de026485802e41e16a1180be2df85e4a) +++ d662b707e11391f6cfe597fd4d0bf9c41d34d01a/Makefile (mode:100644 sha1:b2ce7c5b63fffca59653b980d98379909f893d44) @@ -14,7 +14,7 @@ PROG= update-cache show-diff init-db write-tree read-tree commit-tree \ cat-file fsck-cache checkout-cache diff-tree rev-tree show-files \ - check-files ls-tree + check-files ls-tree merge-base SCRIPT= parent-id tree-id git gitXnormid.sh gitadd.sh gitaddremote.sh \ gitcommit.sh gitdiff-do gitdiff.sh gitlog.sh gitls.sh gitlsobj.sh \ Index: merge-base.c =================================================================== --- /dev/null (tree:37a0b01b85c2999243674d48bfc71cdba0e5518e) +++ d662b707e11391f6cfe597fd4d0bf9c41d34d01a/merge-base.c (mode:100644 sha1:0f85e7d9e9a896d1142a54170ddf1159f11f9cdd) @@ -0,0 +1,108 @@ +#include <stdlib.h> +#include "cache.h" +#include "revision.h" + +struct revision *common_ancestor(struct revision *rev1, struct revision *rev2) +{ + struct parent *parent; + + struct parent *rev1list = malloc(sizeof(struct parent)); + struct parent *rev2list = malloc(sizeof(struct parent)); + + struct parent *posn, *temp; + + rev1list->parent = rev1; + rev1list->next = NULL; + + rev2list->parent = rev2; + rev2list->next = NULL; + + while (rev1list || rev2list) { + posn = rev1list; + rev1list = NULL; + while (posn) { + parse_commit_object(posn->parent); + if (posn->parent->flags & 0x0001) { + /* + printf("1 already seen %s %x\n", + sha1_to_hex(posn->parent->sha1), + posn->parent->flags); + */ + // do nothing + } else if (posn->parent->flags & 0x0002) { + // XXXX free lists + return posn->parent; + } else { + /* + printf("1 based on %s\n", + sha1_to_hex(posn->parent->sha1)); + */ + posn->parent->flags |= 0x0001; + + parent = posn->parent->parent; + while (parent) { + temp = malloc(sizeof(struct parent)); + temp->next = rev1list; + temp->parent = parent->parent; + rev1list = temp; + parent = parent->next; + } + } + posn = posn->next; + } + posn = rev2list; + rev2list = NULL; + while (posn) { + parse_commit_object(posn->parent); + if (posn->parent->flags & 0x0002) { + /* + printf("2 already seen %s\n", + sha1_to_hex(posn->parent->sha1)); + */ + // do nothing + } else if (posn->parent->flags & 0x0001) { + // XXXX free lists + return posn->parent; + } else { + /* + printf("2 based on %s\n", + sha1_to_hex(posn->parent->sha1)); + */ + posn->parent->flags |= 0x0002; + + parent = posn->parent->parent; + while (parent) { + temp = malloc(sizeof(struct parent)); + temp->next = rev2list; + temp->parent = parent->parent; + rev2list = temp; + parent = parent->next; + } + } + posn = posn->next; + } + } + return NULL; +} + +int main(int argc, char **argv) +{ + struct revision *rev1, *rev2, *ret; + unsigned char rev1key[20], rev2key[20]; + if (argc != 3 || + get_sha1_hex(argv[1], rev1key) || + get_sha1_hex(argv[2], rev2key)) { + usage("mergebase <commit-id> <commit-id>"); + } + rev1 = lookup_rev(rev1key); + rev2 = lookup_rev(rev2key); + ret = common_ancestor(rev1, rev2); + if (ret) { + printf("%s\n", sha1_to_hex(ret->sha1)); + return 0; + } else { + printf("Sorry.\n"); + return 1; + } + +} - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html