diff options
| -rw-r--r-- | sha1_name.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/sha1_name.c b/sha1_name.c index 4e9a05233..75c688ecf 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -1,5 +1,8 @@ #include "cache.h" +#include "tag.h" #include "commit.h" +#include "tree.h" +#include "blob.h" static int find_short_object_filename(int len, const char *name, unsigned char *sha1) { @@ -274,6 +277,82 @@ static int get_nth_ancestor(const char *name, int len, return 0; } +static int peel_onion(const char *name, int len, unsigned char *sha1) +{ + unsigned char outer[20]; + const char *sp; + const char *type_string = NULL; + struct object *o; + + /* + * "ref^{type}" dereferences ref repeatedly until you cannot + * dereference anymore, or you get an object of given type, + * whichever comes first. "ref^{}" means just dereference + * tags until you get a non-tag. "ref^0" is a shorthand for + * "ref^{commit}". "commit^{tree}" could be used to find the + * top-level tree of the given commit. + */ + if (len < 4 || name[len-1] != '}') + return -1; + + for (sp = name + len - 1; name <= sp; sp--) { + int ch = *sp; + if (ch == '{' && name < sp && sp[-1] == '^') + break; + } + if (sp <= name) + return -1; + + sp++; /* beginning of type name, or closing brace for empty */ + if (!strncmp(commit_type, sp, 6) && sp[6] == '}') + type_string = commit_type; + else if (!strncmp(tree_type, sp, 4) && sp[4] == '}') + type_string = tree_type; + else if (!strncmp(blob_type, sp, 4) && sp[4] == '}') + type_string = blob_type; + else if (sp[0] == '}') + type_string = NULL; + else + return -1; + + if (get_sha1_1(name, sp - name - 2, outer)) + return -1; + + o = parse_object(outer); + if (!o) + return -1; + if (!type_string) { + o = deref_tag(o); + memcpy(sha1, o->sha1, 20); + } + else { + /* At this point, the syntax look correct, so + * if we do not get the needed object, we should + * barf. + */ + + while (1) { + if (!o) + return -1; + if (o->type == type_string) { + memcpy(sha1, o->sha1, 20); + return 0; + } + if (o->type == tag_type) + o = ((struct tag*) o)->tagged; + else if (o->type == commit_type) + o = &(((struct commit *) o)->tree->object); + else + return error("%.*s: expected %s type, but the object dereferences to %s type", + len, name, type_string, + o->type); + if (!o->parsed) + parse_object(o->sha1); + } + } + return 0; +} + static int get_sha1_1(const char *name, int len, unsigned char *sha1) { int parent, ret; @@ -315,6 +394,10 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1) return get_nth_ancestor(name, len1, sha1, parent); } + ret = peel_onion(name, len, sha1); + if (!ret) + return 0; + ret = get_sha1_basic(name, len, sha1); if (!ret) return 0; |