sed y bug

[utzoo!henry]

The y command of sed(1) has a minor bug:  it does not check properly
for a missing trailing delimiter.  It will catch the missing delimiter
if the command is ended by a newline (i.e. commands are from a file)
but not if the command is ended by a NUL.  So, for example, the
command "sed your old man" dumps core.  The fix is to change the
following line in sed0.c (about line 943):

 		if(*tsp == '\n')
to
 		if(*tsp == '\n' || *tsp == '\0')

Ron Gomes of HCR described this one to me long ago;  Laura Creighton
figured out the exact fix here.