[PATCH] Make nsec checking optional

[git.git] / read-cache.c

diff --git a/read-cache.c b/read-cache.c
index 53da500..f1abae1 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -12,10 +12,12 @@ unsigned int active_nr = 0, active_alloc = 0;
 void usage(const char *err, ...)
 {
        va_list args;
+       char string[200];
 
        va_start(args, err);
-       vfprintf(stderr, err, args);
+       vsnprintf(string, sizeof(string), err, args);
        va_end(args);
+       fprintf(stderr, "%s\n", string);
        exit(1);
 }
 
@@ -214,8 +216,25 @@ int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
        int fd;
 
        fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-       if (fd < 0)
-               return (errno == EEXIST) ? 0 : -1;
+       if (fd < 0) {
+               void *map;
+               static int error(const char * string);
+
+               if (errno != EEXIST)
+                       return -1;
+#ifndef COLLISION_CHECK
+               fd = open(filename, O_RDONLY);
+               if (fd < 0)
+                       return -1;
+               map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+               if (map == MAP_FAILED)
+                       return -1;
+               if (memcmp(buf, map, size))
+                       return error("SHA1 collision detected!"
+                                       " This is bad, bad, BAD!\a\n");
+#endif
+               return 0;
+       }
        write(fd, buf, size);
        close(fd);
        return 0;
@@ -231,11 +250,20 @@ int cache_match_stat(struct cache_entry *ce, struct stat *st)
 {
        unsigned int changed = 0;
 
-       if (ce->mtime.sec  != (unsigned int)st->st_mtim.tv_sec ||
-           ce->mtime.nsec != (unsigned int)st->st_mtim.tv_nsec)
+       /* nsec seems unreliable - not all filesystems support it, so
+        * as long as it is in the inode cache you get right nsec
+        * but after it gets flushed, you get zero nsec. */
+       if (ce->mtime.sec  != (unsigned int)st->st_mtim.tv_sec
+#ifdef NSEC
+           || ce->mtime.nsec != (unsigned int)st->st_mtim.tv_nsec
+#endif
+           )
                changed |= MTIME_CHANGED;
-       if (ce->ctime.sec  != (unsigned int)st->st_ctim.tv_sec ||
-           ce->ctime.nsec != (unsigned int)st->st_ctim.tv_nsec)
+       if (ce->ctime.sec  != (unsigned int)st->st_ctim.tv_sec
+#ifdef NSEC
+           || ce->ctime.nsec != (unsigned int)st->st_ctim.tv_nsec
+#endif
+           )
                changed |= CTIME_CHANGED;
        if (ce->st_uid != (unsigned int)st->st_uid ||
            ce->st_gid != (unsigned int)st->st_gid)
@@ -276,24 +304,23 @@ int cache_name_pos(const char *name, int namelen)
                struct cache_entry *ce = active_cache[next];
                int cmp = cache_name_compare(name, namelen, ce->name, ce->namelen);
                if (!cmp)
-                       return -next-1;
+                       return next;
                if (cmp < 0) {
                        last = next;
                        continue;
                }
                first = next+1;
        }
-       return first;
+       return -first-1;
 }
 
 int remove_file_from_cache(char *path)
 {
        int pos = cache_name_pos(path, strlen(path));
-       if (pos < 0) {
-               pos = -pos-1;
+       if (pos >= 0) {
                active_nr--;
                if (pos < active_nr)
-                       memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos - 1) * sizeof(struct cache_entry *));
+                       memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *));
        }
        return 0;
 }
@@ -305,10 +332,11 @@ int add_cache_entry(struct cache_entry *ce, int ok_to_add)
        pos = cache_name_pos(ce->name, ce->namelen);
 
        /* existing match? Just replace it */
-       if (pos < 0) {
-               active_cache[-pos-1] = ce;
+       if (pos >= 0) {
+               active_cache[pos] = ce;
                return 0;
        }
+       pos = -pos-1;
 
        if (!ok_to_add)
                return -1;
@@ -362,7 +390,7 @@ int read_cache(void)
                sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
        if (access(sha1_file_directory, X_OK) < 0)
                return error("no access to SHA1 file directory");
-       fd = open(".dircache/index", O_RDONLY);
+       fd = open(".git/index", O_RDONLY);
        if (fd < 0)
                return (errno == ENOENT) ? 0 : error("open failed");