Master/Relay Log Info files ignore trailing garbage and overflows in numeric lines

Question for QA

This issue should never occur from proper use, but only when a DBA user or app externally modifies those plain-text internal files (rather than using CHANGE MASTER) to an invalid state.
So, should we address this at all, if the root problem is this DBA shooting themself in their foot?

Description

When the parsers of @@master_info_file or @@relay_log_info_file read lines for number fields (integer or MASTER_HEARTBEAT_PERIOD), they

• ignore unrecognized (e.g., non-numeric) content at the end of the line; and
• does not consume the entire line, only up to 31 (integer) or 15 (MASTER_HEARTBEAT_PERIOD) bytes, leaving the rest to be picked up as the following line instead.

For example, this reduced Master Info file does not cause an error –

17

4

127.0.0.1

root

3306abcdefghijklmnopqrstuvwxyz&10

60

0

0

60.000abcdefghijklm

1 1

– but is read with the 3306… as both the MASTER_PORT and MASTER_CONNECT_RETRY fields.

Master_Port = '3306'

Connect_Retry = '10'