CORE-11857 CORE-13736
It will be followed with a separate fix for the FOR-loop code.
Fixes some cmd_winetests.
A NULL pointer can be returned for a valid existing batch/FOR variable,
in which case the enhanced-variable getter should return an empty string.
This situation can happen e.g. when forcing a FOR-loop to tokenize a
text line with not enough tokens in it.
CORE-13713 CORE-13736
- In case execution of all batch contexts is stopped (by selecting "All"
at the Ctrl-C/Ctrl-Break prompt), notify as well the CheckCtrlBreak()
signal handler once there are no more batch contexts (this in effect
resets the internal 'bLeaveAll' static flag in CheckCtrlBreak).
This is an adaptation of the fix present in FreeCOM 1.5, first
described in https://gcfl.net/FreeDOS/command.com/bugs074g.html .
- Introduce a ParseErrorEx() helper that sets the 'bParseError' flag and
displays a customized syntax-error message, only for the first syntax
error encountered. Implement ParseError() around the *Ex function.
- In batch mode, echo the original pre-parsed batch file line if a parse
error has been encountered.
- When running a compound command - including IF, FOR, command blocks -,
and that control flow is modified by any CALL/GOTO/EXIT command,
detect this while running the compound command so as to stop it and go
back to the main batch execution loop, that will then set up the actual
new command to run.
- In GOTO, do not process any more parts of a compound command only when
we have found a valid label.
