Bug #90853 warning: taking the max of a value and unsigned zero is always equal to the othe
Submitted: 14 May 6:19 Modified: 14 May 9:57
Reporter: Shane Bester (Platinum Quality Contributor) Email Updates:
Status: Duplicate Impact on me:
None 
Category:MySQL Server: Compiling Severity:S3 (Non-critical)
Version:5.7.22 OS:FreeBSD (11.1)
Assigned to: CPU Architecture:Any

[14 May 6:19] Shane Bester
Description:
During compile on freebsd, saw a few of these:

In file included from ./mysql-5.7.22/sql/sql_optimizer.cc:37:
./mysql-5.7.22/sql/sql_join_buffer.h:347:12: warning: taking the max of a value and unsigned zero is always equal to the other value [-Wmax-unsigned-zero]
    return std::max<ulong>(buff_size-(end_pos-buff)-aux_buff_size, 0UL);
           ^~~~~~~~~~~~~~~                                         ~~~

./mysql-5.7.22/sql/sql_join_buffer.h:815:12: warning: taking the max of a value and unsigned zero is always equal to the other value [-Wmax-unsigned-zero]
    return std::max(static_cast<ulong>(last_key_entry - end_pos-aux_buff_size),
           ^~~~~~~~

Note sure if this is specific to freebsd or not, but the warning makes sense anyway.

How to repeat:
compile...
[14 May 9:57] Shane Bester
Already filed as https://bugs.mysql.com/bug.php?id=89419
[14 May 10:04] Shane Bester
fixed in 8.0 by
Bug#24796251 ADD DEBUG CHECKS TO JOIN_CACHE