Re: empty quotes break pattern replacements in bash-4.2

[Chet Ramey]

On 2/18/11 9:06 PM, Mike Frysinger wrote:
> this simple code no longer works in bash-4.2:
> $ f=abc; echo ${f##""a}
> abc
> same goes for ${f//""a} and ${f%%""c}, and perhaps more operations

One more: everything that calls getpattern().

> removing the quotes, or quoting the single char in question, makes it work:
> $ f=abc; echo ${f##a} ${f##"a"}
> bc bc
> 
> the original bug report uses variables in the pattern and quotes them to 
> avoid 
> expansion of globs and such.  but if the variable happened to be empty, 
> things 
> no longer worked correctly.

Try this patch.

Chet
-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    c...@case.edu    http://cnswww.cns.cwru.edu/~chet/

*** ../bash-4.2/subst.c	2011-01-02 16:12:51.000000000 -0500
--- subst.c	2011-02-18 22:30:13.000000000 -0500
***************
*** 3371,3377 ****
    if (string == 0 || *string == '\0')
      return (WORD_LIST *)NULL;
  
!   td.flags = 0;
    td.word = string;
    tresult = call_expand_word_internal (&td, quoted, 1, dollar_at_p, has_dollar_at);
    return (tresult);
--- 3375,3381 ----
    if (string == 0 || *string == '\0')
      return (WORD_LIST *)NULL;
  
!   td.flags = W_NOSPLIT2;		/* no splitting, remove "" and '' */
    td.word = string;
    tresult = call_expand_word_internal (&td, quoted, 1, dollar_at_p, has_dollar_at);
    return (tresult);