bug#14390: 24.3.50; (wrong-type-argument stringp t) from `read-regexp'

["Drew Adams" <drew.adams@oracle.com>]

The backtrace is not from emacs -Q, but I think the same problem is there.
 
`read-regexp' binds SUGGESTIONS to this:
 
(append
  suggestions
  (list
   (find-tag-default-as-regexp) ; <======= SHOULD return a string
   (car regexp-search-ring)
   (regexp-quote (or (car search-ring) ""))
   (car (symbol-value query-replace-from-history-variable))))
 
The problem is (find-tag-default-as-regexp), which will return `t' when
TAG is nil.  `t' is not a valid suggestion: SUGGESTIONS must be a list
of strings.
 
Debugger entered--Lisp error: (wrong-type-argument stringp t)
* icicle-ORIG-read-from-minibuffer("Flush lines containing match for regexp: " t
nil nil regexp-history (t "^\\*.*" "keep-lines-read-args"
"bookmarkp-bmenu-show-only-varlists") t)
* read-from-minibuffer("Flush lines containing match for regexp: " nil nil nil
regexp-history (t "^\\*.*" "keep-lines-read-args"
"bookmarkp-bmenu-show-only-varlists") t)
* read-regexp("Flush lines containing match for regexp")
* (list (read-regexp prompt) nil nil t)
* (lambda (prompt) "Read arguments for `keep-lines' and friends.\nPrompt for a
regexp with PROMPT.\nValue is a list, (REGEXP)." (list (read-regexp prompt) nil
nil t))("Flush lines containing match for regexp")
* apply((lambda (prompt) "Read arguments for `keep-lines' and friends.\nPrompt
for a regexp with PROMPT.\nValue is a list, (REGEXP)." (list (read-regexp
prompt) nil nil t)) "Flush lines containing match for regexp")
* keep-lines-read-args("Flush lines containing match for regexp")
  (progn (barf-if-buffer-read-only) (keep-lines-read-args "Flush lines
containing match for regexp"))
  call-interactively(flush-lines record-it)
  icicle-execute-extended-command-1("flush-lines")
  ...
  funcall(...)
  icicle-execute-extended-command()
  call-interactively(icicle-execute-extended-command nil nil)
  command-execute(icicle-execute-extended-command)
 
 
 

In GNU Emacs 24.3.50.1 (i386-mingw-nt5.1.2600)
 of 2013-05-10 on ODIEONE
Bzr revision: 112542 rgm@gnu.org-20130510102119-fklj7xlajezey0tr
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.7) --no-opt --enable-checking --cflags
 -IC:/Devel/emacs/build/include --ldflags -LC:/Devel/emacs/build/lib'