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.
*** 'a\nc\n\n\n\n' 'a\nb\n\n\n'
*** 'a\nb\nc\n' 'a\nc\n'
*** '' ''
*** 'a\nb\nc' 'a\nb\nc'
*** 'a\nb\nc\nd\n' 'a\nd\n'
*** 'a\nb\nc\nd\n' 'a\nc\ne\n'
*** 'a\nb\nc\n' 'a\nc\n'
*** 'a\n' 'c\na\nb\n'
*** 'a\n' ''
*** 'a\n' 'b\nc\n'
*** 'a\n' 'c\na\n'
*** '' 'adjfkjdjksdhfksj'
*** '' 'ab'
*** '' 'abc'
*** 'a' 'a'
*** 'ab' 'ab'
*** 'abc' 'abc'
*** 'a\n' 'a\n'
*** 'a\nb' 'a\nb'
6 6 'y\n\n'
6 6 'y\n\n'
9 9 'y\n\n'
done
done