Subject: bug#14563: Add prefix arg to more isearch commands

From: Juri Linkov <[email-masked]>
Date: Fri, 14 Jun 2013 00:12:11 +0300

Additionally, I also fixed the existing arg of `isearch-del-char'
for the case where it failed when its arg is larger than the length
of the search string.  The test case is `C-s C-M-y C-u 2 C-M-w'.