bug in man -f (whatis) in 4.3bsd

[Joe Ramey]

Whatis occasionally won't find in summary lines after commands
containing underscores.

Example: (this example is actually from SunOS 4.0, though the bug is
also in 4.3bsd man)

% whatis perror
perror, sys_errlist, sys_nerr, errno (3)    - system error messages
% whatis errno
man: man entry for errno not found.

Fix:
590c590
< 	while (isalpha(*bp) || isdigit(*bp))
---
> 	while (isalpha(*bp) || isdigit(*bp) || (*bp == '_'))

Joe Ramey
TI Computer Science Center