[PATCH/7.6] Fix wrong release (maybe crash GDB) in build_target_command_list

[Tom Tromey]

>>>>> "Hui" == Hui Zhu <teawater@gmail.com> writes:

Hui> I tried but looks free conditions cannot crash GDB.  :(

I was wondering if there could be a non-crashing reproducer.
It seems a little tricky.

I think this particular patch is ok without a test though.
Please check it in.

>> The "continue" seems to mean that null_command_or_parse_error will not
>> be set in the "parse error" case.

Hui> I think it is right, because even if one of breakpoint loc doesn't
Hui> have commands.  GDB still need send other commands to target.

I think that would be an argument for removing the "break" -- but not
necessarily for keeping the "continue".

The "return" in the null_command_or_parse_error case also seems weird to
me, but I didn't think hard about it.

Tom