manifest.c: ensure realloc_if_full() returns 1 or 0
This fixes an MSVC 2008 warning that I don't see with gcc 4.6.3-2:
warning C4047: 'return' :
'bool' differs in levels of indirection from 'line *'
More importantly, the truncation from pointer to 'unsigned char' would have
returned 0 if self->lines pointed to an address divisible by 0xFF, which causes
find_lines() to return MANIFEST_OOM. I was able to cause this to happen in a
trivial program with the gcc compiler.
% lazy ancestor set for [], stoprev = 0, inclusive = False
membership: []
iteration: []
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = False
membership: [7, 8, 3, 4, 1, 0]
iteration: [3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [1, 3], stoprev = 0, inclusive = False
membership: [1, 0]
iteration: [0, 1]
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = True
membership: [11, 13, 7, 8, 3, 4, 1, 0]
iteration: [11, 13, 3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = False
membership: [7, 8]
iteration: [7, 8]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = True
membership: [11, 13, 7, 8]
iteration: [11, 13, 7, 8]