On 3/19/12 9:27 AM, Mark Edgar wrote: > I've boiled the problem down to this: > > A= > B=q > echo "x${A+${B#q*}}x" | sed -nel > > Excluding the newline, the output I expect is "xx", but instead there > is a delete character \177 between the two "x" characters.
Thanks for the wonderfully detailed bug report; that made the problem easy to find and test. I've attached a patch which fixes the issue. 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-patched/subst.c 2012-03-11 17:35:13.000000000 -0400 --- subst.c 2012-03-20 19:30:13.000000000 -0400 *************** *** 5805,5808 **** --- 5814,5827 ---- if (qdollaratp && ((hasdol && quoted) || l->next)) *qdollaratp = 1; + /* If we have a quoted null result (QUOTED_NULL(temp)) and the word is + a quoted null (l->next == 0 && QUOTED_NULL(l->word->word)), the + flags indicate it (l->word->flags & W_HASQUOTEDNULL), and the + expansion is quoted (quoted & (Q_HERE_DOCUMENT|Q_DOUBLE_QUOTES)) + (which is more paranoia than anything else), we need to return the + quoted null string and set the flags to indicate it. */ + if (l->next == 0 && (quoted & (Q_HERE_DOCUMENT|Q_DOUBLE_QUOTES)) && QUOTED_NULL(temp) && QUOTED_NULL(l->word->word) && (l->word->flags & W_HASQUOTEDNULL)) + { + w->flags |= W_HASQUOTEDNULL; + } dispose_words (l); }