Don't open streams or stdin on non-matching directives.

* match.c (open_data_source): The logic of not opening
the data source for a non-matching directive must be applied
to streams also, because the lazy list mechanism will read
ahead from an underlying non-interactive stream. We must
also apply it in the case when we open standard input by
default. If standard input is non-interactive such that the
lazy list unconditionally tries to read a line from it
upon construction, we misbehave. The program could block
on the read. Even if it doesn't block, the input action is
an unwanted externally visible event.

0 files changed, 0 insertions, 0 deletions