cache.c: fix error checking in print_slot()

The change to print_slot() in cdc6b2f8e7a8d43dcfe0475a9d3498333ea686b8 made
the function return correct errno for read errors while ignoring write errors,
which is not what was intended. This patch tries to rectify things.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 7 insertions, 4 deletions

@@ -81,16 +81,19 @@ static int close_slot(struct cache_slot *slot)
 /* Print the content of the active cache slot (but skip the key). */
 static int print_slot(struct cache_slot *slot)
 {
-        ssize_t i;
+        ssize_t i, j;
 
         i = lseek(slot->cache_fd, slot->keylen + 1, SEEK_SET);
         if (i != slot->keylen + 1)
                 return errno;
 
-        while((i = xread(slot->cache_fd, slot->buf, sizeof(slot->buf))) > 0)
-                i = xwrite(STDOUT_FILENO, slot->buf, i);
+        do {
+                i = j = xread(slot->cache_fd, slot->buf, sizeof(slot->buf));
+                if (i > 0)
+                        j = xwrite(STDOUT_FILENO, slot->buf, i);
+        } while (i > 0 && j == i);
 
-        if (i < 0)
+        if (i < 0 || j != i)
                 return errno;
         else
                 return 0;