Fix bug found by Derrell - windows returns an read return

offset of zero if return size is zero. Should fix testread
libsmbclient code.
Jeremy.

diff --git a/source/libsmb/clireadwrite.c b/source/libsmb/clireadwrite.c
index 6b39a885f04262467bb8ec267ef158cc3360cc07..af13ed8f7337775377fe646aa01c797c188524d5 100644 (file)
--- a/source/libsmb/clireadwrite.c
+++ b/source/libsmb/clireadwrite.c
@@ -134,6 +134,8 @@ ssize_t cli_read(struct cli_state *cli, int fnum, char *buf, off_t offset, size_
                                 return -1;
                }
 
+               /* size2 is the number of bytes the server returned.
+                * Might be zero. */
                size2 = SVAL(cli->inbuf, smb_vwv5);
                size2 |= (((unsigned int)(SVAL(cli->inbuf, smb_vwv7))) << 16);
 
@@ -145,27 +147,32 @@ ssize_t cli_read(struct cli_state *cli, int fnum, char *buf, off_t offset, size_
                        return -1;
                }
 
-               if (!direct_reads) {
-                       /* Copy data into buffer */
-                       p = smb_base(cli->inbuf) + SVAL(cli->inbuf,smb_vwv6);
-                       memcpy(buf + total, p, size2);
-               } else {
-                       /* Ensure the remaining data matches the return size. */
-                       ssize_t toread = smb_len_large(cli->inbuf) - SVAL(cli->inbuf,smb_vwv6);
-
-                       /* Ensure the size is correct. */
-                       if (toread != size2) {
-                               DEBUG(5,("direct read logic fail toread (%d) != size2 (%u)\n",
-                                       (int)toread, (unsigned int)size2 ));
-                               return -1;
-                       }
-
-                       /* Read data directly into buffer */
-                       toread = cli_receive_smb_data(cli,buf+total,size2);
-                       if (toread != size2) {
-                               DEBUG(5,("direct read read failure toread (%d) != size2 (%u)\n",
-                                       (int)toread, (unsigned int)size2 ));
-                               return -1;
+               if (size2) {
+                       /* smb_vwv6 is the offset in the packet of the returned
+                        * data bytes. Only valid if size2 != 0. */
+
+                       if (!direct_reads) {
+                               /* Copy data into buffer */
+                               p = smb_base(cli->inbuf) + SVAL(cli->inbuf,smb_vwv6);
+                               memcpy(buf + total, p, size2);
+                       } else {
+                               /* Ensure the remaining data matches the return size. */
+                               ssize_t toread = smb_len_large(cli->inbuf) - SVAL(cli->inbuf,smb_vwv6);
+
+                               /* Ensure the size is correct. */
+                               if (toread != size2) {
+                                       DEBUG(5,("direct read logic fail toread (%d) != size2 (%u)\n",
+                                               (int)toread, (unsigned int)size2 ));
+                                       return -1;
+                               }
+
+                               /* Read data directly into buffer */
+                               toread = cli_receive_smb_data(cli,buf+total,size2);
+                               if (toread != size2) {
+                                       DEBUG(5,("direct read read failure toread (%d) != size2 (%u)\n",
+                                               (int)toread, (unsigned int)size2 ));
+                                       return -1;
+                               }
                        }
                }