cache.c: read(2) returns -1 on error, not 0

Noticed-by: Jim Meyering <jim@meyering.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/cache.c b/cache.c
index b701e13..add647e 100644
--- a/cache.c
+++ b/cache.c
@@ -7,97 +7,97 @@
  *
  *
  * The cache is just a directory structure where each file is a cache slot,
  * and each filename is based on the hash of some key (e.g. the cgit url).
  * Each file contains the full key followed by the cached content for that
  * key.
  *
  */
 
 #include "cgit.h"
 #include "cache.h"
 
 #define CACHE_BUFSIZE (1024 * 4)
 
 struct cache_slot {
         const char *key;
         int keylen;
         int ttl;
         cache_fill_fn fn;
         void *cbdata;
         int cache_fd;
         int lock_fd;
         const char *cache_name;
         const char *lock_name;
         int match;
         struct stat cache_st;
         struct stat lock_st;
         int bufsize;
         char buf[CACHE_BUFSIZE];
 };
 
 /* Open an existing cache slot and fill the cache buffer with
  * (part of) the content of the cache file. Return 0 on success
  * and errno otherwise.
  */
 static int open_slot(struct cache_slot *slot)
 {
         char *bufz;
         int bufkeylen = -1;
 
         slot->cache_fd = open(slot->cache_name, O_RDONLY);
         if (slot->cache_fd == -1)
                 return errno;
 
         if (fstat(slot->cache_fd, &slot->cache_st))
                 return errno;
 
         slot->bufsize = read(slot->cache_fd, slot->buf, sizeof(slot->buf));
-        if (slot->bufsize == 0)
+        if (slot->bufsize < 0)
                 return errno;
 
         bufz = memchr(slot->buf, 0, slot->bufsize);
         if (bufz)
                 bufkeylen = bufz - slot->buf;
 
         slot->match = bufkeylen == slot->keylen &&
             !memcmp(slot->key, slot->buf, bufkeylen + 1);
 
         return 0;
 }
 
 /* Close the active cache slot */
 static void close_slot(struct cache_slot *slot)
 {
         if (slot->cache_fd > 0) {
                 close(slot->cache_fd);
                 slot->cache_fd = -1;
         }
 }
 
 /* Print the content of the active cache slot (but skip the key). */
 static int print_slot(struct cache_slot *slot)
 {
         ssize_t i, j = 0;
 
         i = lseek(slot->cache_fd, slot->keylen + 1, SEEK_SET);
         if (i != slot->keylen + 1)
                 return errno;
 
         while((i=read(slot->cache_fd, slot->buf, sizeof(slot->buf))) > 0)
                 j = write(STDOUT_FILENO, slot->buf, i);
 
         if (j < 0)
                 return errno;
         else
                 return 0;
 }
 
 /* Check if the slot has expired */
 static int is_expired(struct cache_slot *slot)
 {
         if (slot->ttl < 0)
                 return 0;
         else
                 return slot->cache_st.st_mtime + slot->ttl*60 < time(NULL);
 }