diff options
Diffstat (limited to 'sql/mf_iocache.cc')
| -rw-r--r-- | sql/mf_iocache.cc | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/sql/mf_iocache.cc b/sql/mf_iocache.cc index 7f85cc06f57..c1e6b37a848 100644 --- a/sql/mf_iocache.cc +++ b/sql/mf_iocache.cc @@ -240,12 +240,17 @@ int _my_b_read(register IO_CACHE *info, byte *Buffer, uint Count) { uint length,diff_length,left_length; my_off_t max_length, pos_in_file; - - memcpy(Buffer,info->rc_pos, - (size_t) (left_length=(uint) (info->rc_end-info->rc_pos))); - Buffer+=left_length; - Count-=left_length; - pos_in_file=info->pos_in_file+(uint) (info->rc_end - info->buffer); + + if((left_length=(uint) (info->rc_end-info->rc_pos))) + { + if(Count < left_length) + left_length = Count; + memcpy(Buffer,info->rc_pos, + (size_t) (left_length)); + Buffer+=left_length; + Count-=left_length; + } + pos_in_file=info->pos_in_file+ left_length; if (info->seek_not_done) { /* File touched, do seek */ VOID(my_seek(info->file,pos_in_file,MY_SEEK_SET,MYF(0))); |