diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | commit.h | 2 | ||||
| -rw-r--r-- | replace_object.c | 111 | ||||
| -rw-r--r-- | sha1_file.c | 14 |
4 files changed, 125 insertions, 3 deletions
@@ -512,6 +512,7 @@ LIB_OBJS += read-cache.o LIB_OBJS += reflog-walk.o LIB_OBJS += refs.o LIB_OBJS += remote.o +LIB_OBJS += replace_object.o LIB_OBJS += rerere.o LIB_OBJS += revision.o LIB_OBJS += run-command.o @@ -124,6 +124,8 @@ struct commit_graft *read_graft_line(char *buf, int len); int register_commit_graft(struct commit_graft *, int); struct commit_graft *lookup_commit_graft(const unsigned char *sha1); +const unsigned char *lookup_replace_object(const unsigned char *sha1); + extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2, int cleanup); extern struct commit_list *get_merge_bases_many(struct commit *one, int n, struct commit **twos, int cleanup); extern struct commit_list *get_octopus_merge_bases(struct commit_list *in); diff --git a/replace_object.c b/replace_object.c new file mode 100644 index 0000000000..b23e1cd52a --- /dev/null +++ b/replace_object.c @@ -0,0 +1,111 @@ +#include "cache.h" +#include "sha1-lookup.h" +#include "refs.h" + +static struct replace_object { + unsigned char sha1[2][20]; +} **replace_object; + +static int replace_object_alloc, replace_object_nr; + +static const unsigned char *replace_sha1_access(size_t index, void *table) +{ + struct replace_object **replace = table; + return replace[index]->sha1[0]; +} + +static int replace_object_pos(const unsigned char *sha1) +{ + return sha1_pos(sha1, replace_object, replace_object_nr, + replace_sha1_access); +} + +static int register_replace_object(struct replace_object *replace, + int ignore_dups) +{ + int pos = replace_object_pos(replace->sha1[0]); + + if (0 <= pos) { + if (ignore_dups) + free(replace); + else { + free(replace_object[pos]); + replace_object[pos] = replace; + } + return 1; + } + pos = -pos - 1; + if (replace_object_alloc <= ++replace_object_nr) { + replace_object_alloc = alloc_nr(replace_object_alloc); + replace_object = xrealloc(replace_object, + sizeof(*replace_object) * + replace_object_alloc); + } + if (pos < replace_object_nr) + memmove(replace_object + pos + 1, + replace_object + pos, + (replace_object_nr - pos - 1) * + sizeof(*replace_object)); + replace_object[pos] = replace; + return 0; +} + +static int register_replace_ref(const char *refname, + const unsigned char *sha1, + int flag, void *cb_data) +{ + /* Get sha1 from refname */ + const char *slash = strrchr(refname, '/'); + const char *hash = slash ? slash + 1 : refname; + struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj)); + + if (strlen(hash) != 40 || get_sha1_hex(hash, repl_obj->sha1[0])) { + free(repl_obj); + warning("bad replace ref name: %s", refname); + return 0; + } + + /* Copy sha1 from the read ref */ + hashcpy(repl_obj->sha1[1], sha1); + + /* Register new object */ + if (register_replace_object(repl_obj, 1)) + die("duplicate replace ref: %s", refname); + + return 0; +} + +static void prepare_replace_object(void) +{ + static int replace_object_prepared; + + if (replace_object_prepared) + return; + + for_each_replace_ref(register_replace_ref, NULL); + replace_object_prepared = 1; +} + +/* We allow "recursive" replacement. Only within reason, though */ +#define MAXREPLACEDEPTH 5 + +const unsigned char *lookup_replace_object(const unsigned char *sha1) +{ + int pos, depth = MAXREPLACEDEPTH; + const unsigned char *cur = sha1; + + prepare_replace_object(); + + /* Try to recursively replace the object */ + do { + if (--depth < 0) + die("replace depth too high for object %s", + sha1_to_hex(sha1)); + + pos = replace_object_pos(cur); + if (0 <= pos) + cur = replace_object[pos]->sha1[1]; + } while (0 <= pos); + + return cur; +} diff --git a/sha1_file.c b/sha1_file.c index e73cd4fc0b..4bf24ffcf6 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -2148,10 +2148,18 @@ static void *read_object(const unsigned char *sha1, enum object_type *type, void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size) { - void *data = read_object(sha1, type, size); + const unsigned char *repl = lookup_replace_object(sha1); + void *data = read_object(repl, type, size); + + /* die if we replaced an object with one that does not exist */ + if (!data && repl != sha1) + die("replacement %s not found for %s", + sha1_to_hex(repl), sha1_to_hex(sha1)); + /* legacy behavior is to die on corrupted objects */ - if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1))) - die("object %s is corrupted", sha1_to_hex(sha1)); + if (!data && (has_loose_object(repl) || has_packed_and_bad(repl))) + die("object %s is corrupted", sha1_to_hex(repl)); + return data; } |