Reject invalid formatted scanf character data with the 'c' conversion
where there is not enough input available to satisfy the field width
requested. It is required by ISO C that this conversion matches a
sequence of characters of exactly the number specified by the field
width and it is also already documented as such in our own manual:
"It reads precisely the next N characters, and fails if it cannot get
that many."
Currently a matching success is instead incorrectly produced where the
EOF condition is encountered before the required number of characters
has been retrieved, and the characters actually obtained are stored in
the buffer provided.
Add test cases accordingly and remove placeholders from 'c' conversion
input data for the existing scanf tests.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add a collection of tests for formatted scanf input specifiers covering
the b, d, i, o, u, x, and X integer conversions, the a, A, e, E, f, F,
g, and G floating-point conversions, and the [, c, and s character
conversions. Also the hh, h, l, and ll length modifiers are covered
with the integer conversions as are the l and L length modifier with the
floating-point conversions. The tests cover assignment suppressing and
the field width as well, verifying the number of assignments made, the
number of characters consumed and the value assigned.
Add the common test code here as well as test cases for scanf, and then
base Makefile infrastructure plus target-agnostic input data, for the
character conversions and the `char', `short', and `long long' integer
ones, signed and unsigned, with remaining input data and other functions
from the scanf family deferred to subsequent additions.
Keep input data disabled and referring to BZ #12701 for entries that are
currently incorrectly accepted as valid data, such as '0b' or '0x' with
the relevant integer conversions or sequences of an insufficient number
of characters with the c conversion.
Reviewed-by: Joseph Myers <josmyers@redhat.com>
