Block or alt after groups separated by semicolons assumes parent's indentation as first group's

[miffi]

The snippet of shrubbery code below does not parse.

a; b
   | c

However, the snippet below does, and its parsed output is (multi (group a) (group b (alts (block (group c))))).

a; b
| c

This means that the parser is inferring the group b's indentation to be at the start of the line. This is different from other cases of syntax forms where multiple groups are separated horizontally, like in opener-closers, where b's alt branch would have to be aligned with its start to compile. Therefore, I think the parser should change to parse the first snippet instead of the second.

P.S. This also affects blocks. This compiles and gives (multi (group a) (group b (block (group c))))

a; b:
 c