too eager expansion in substitution

[Thorsten Glaser]

“If word is not needed, it shall not be expanded.” (POSIX)

00:52 < izabera> i=42; : ${var#${q[i=777]}}; echo $i; var=meow; : ${var#${q[i=777]}}; echo $i
00:52 < izabera> prints 42 777 in bash and ksh93
00:52 < izabera> and 777 777 in mkmsh

The #/##/%/%% of course need to expand word first.

Thanks to jilles for the heads-up.

[Thorsten Glaser (mirabilos)]

Found to be not a bug:

$ i=42; : ${var#${q[i=777]}}; echo $i; var=meow; : ${var#${q[i=777]}}; echo $i

must return 777 twice, because the pattern must always be expanded before looking at $var.

$ i=42; : ${var+${q[i=777]}}; echo $i; var=meow; : ${var+${q[i=777]}}; echo $i

already behaves correctly (42 then 777).