commit.con commit diff-tree: fix "whole sub-tree disappeared or appeared" case (ed1a368)
   1#include "commit.h"
   2#include "cache.h"
   3#include <string.h>
   4#include <limits.h>
   5
   6const char *commit_type = "commit";
   7
   8struct commit *lookup_commit(unsigned char *sha1)
   9{
  10        struct object *obj = lookup_object(sha1);
  11        if (!obj) {
  12                struct commit *ret = xmalloc(sizeof(struct commit));
  13                memset(ret, 0, sizeof(struct commit));
  14                created_object(sha1, &ret->object);
  15                ret->object.type = commit_type;
  16                return ret;
  17        }
  18        if (obj->type != commit_type) {
  19                error("Object %s is a %s, not a commit", 
  20                      sha1_to_hex(sha1), obj->type);
  21                return NULL;
  22        }
  23        return (struct commit *) obj;
  24}
  25
  26static unsigned long parse_commit_date(const char *buf)
  27{
  28        unsigned long date;
  29
  30        if (memcmp(buf, "author", 6))
  31                return 0;
  32        while (*buf++ != '\n')
  33                /* nada */;
  34        if (memcmp(buf, "committer", 9))
  35                return 0;
  36        while (*buf++ != '>')
  37                /* nada */;
  38        date = strtoul(buf, NULL, 10);
  39        if (date == ULONG_MAX)
  40                date = 0;
  41        return date;
  42}
  43
  44int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
  45{
  46        void *bufptr = buffer;
  47        unsigned char parent[20];
  48
  49        if (item->object.parsed)
  50                return 0;
  51        item->object.parsed = 1;
  52        get_sha1_hex(bufptr + 5, parent);
  53        item->tree = lookup_tree(parent);
  54        if (item->tree)
  55                add_ref(&item->object, &item->tree->object);
  56        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
  57        while (!memcmp(bufptr, "parent ", 7) &&
  58               !get_sha1_hex(bufptr + 7, parent)) {
  59                struct commit *new_parent = lookup_commit(parent);
  60                if (new_parent) {
  61                        commit_list_insert(new_parent, &item->parents);
  62                        add_ref(&item->object, &new_parent->object);
  63                }
  64                bufptr += 48;
  65        }
  66        item->date = parse_commit_date(bufptr);
  67        return 0;
  68}
  69
  70int parse_commit(struct commit *item)
  71{
  72        char type[20];
  73        void *buffer;
  74        unsigned long size;
  75        int ret;
  76
  77        if (item->object.parsed)
  78                return 0;
  79        buffer = read_sha1_file(item->object.sha1, type, &size);
  80        if (!buffer)
  81                return error("Could not read %s",
  82                             sha1_to_hex(item->object.sha1));
  83        if (strcmp(type, commit_type)) {
  84                free(buffer);
  85                return error("Object %s not a commit",
  86                             sha1_to_hex(item->object.sha1));
  87        }
  88        ret = parse_commit_buffer(item, buffer, size);
  89        free(buffer);
  90        return ret;
  91}
  92
  93void commit_list_insert(struct commit *item, struct commit_list **list_p)
  94{
  95        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
  96        new_list->item = item;
  97        new_list->next = *list_p;
  98        *list_p = new_list;
  99}
 100
 101void free_commit_list(struct commit_list *list)
 102{
 103        while (list) {
 104                struct commit_list *temp = list;
 105                list = temp->next;
 106                free(temp);
 107        }
 108}
 109
 110static void insert_by_date(struct commit_list **list, struct commit *item)
 111{
 112        struct commit_list **pp = list;
 113        struct commit_list *p;
 114        while ((p = *pp) != NULL) {
 115                if (p->item->date < item->date) {
 116                        break;
 117                }
 118                pp = &p->next;
 119        }
 120        commit_list_insert(item, pp);
 121}
 122
 123        
 124void sort_by_date(struct commit_list **list)
 125{
 126        struct commit_list *ret = NULL;
 127        while (*list) {
 128                insert_by_date(&ret, (*list)->item);
 129                *list = (*list)->next;
 130        }
 131        *list = ret;
 132}
 133
 134struct commit *pop_most_recent_commit(struct commit_list **list,
 135                                      unsigned int mark)
 136{
 137        struct commit *ret = (*list)->item;
 138        struct commit_list *parents = ret->parents;
 139        struct commit_list *old = *list;
 140
 141        *list = (*list)->next;
 142        free(old);
 143
 144        while (parents) {
 145                struct commit *commit = parents->item;
 146                parse_commit(commit);
 147                if (!(commit->object.flags & mark)) {
 148                        commit->object.flags |= mark;
 149                        insert_by_date(list, commit);
 150                }
 151                parents = parents->next;
 152        }
 153        return ret;
 154}