vpath directive with multiple '%' characters in pattern

[Robert P. J. Day]

  out of curiosity, when i read that "A vpath pattern is a string
containing a `%' character.", i thought, is it allowed to contain more
than a single '%' character, so i tested it.

  apparently, a pattern with more than one '%' is not acceptable, but you 
don't find out about this until you actually try to use it in a rule.  
wouldn't it make more sense to immediately flag that vpath directive as 
being invalid?

rday

p.s.  the actual error was

make: *** No rule to make target `jffs2_fs_i.h', needed by `t1'.  Stop.

when i was trying to match the pattern 'jffs%fs%.h'.  if it weren't for 
the fact that i was *explicitly* testing to see what happened in that 
case, i might have been confused for a while trying to track down what had 
happened.