master d1b8179: Switch to literal mode with message when regexp is too big in char-fold search

[Juri Linkov]

branch: master
commit d1b8179f55da75fce313118502ba65444ee1dc98
Author: Juri Linkov <address@hidden>
Commit: Juri Linkov <address@hidden>

    Switch to literal mode with message when regexp is too big in char-fold 
search
    
    * lisp/char-fold.el (char-fold-to-regexp): Don't use regexp-quote
    when the length of regexp reaches 5000.  (Bug#40216)
    
    * lisp/isearch.el (isearch-search): On big regexp in char-fold mode
    gracefully fall back to literal mode, try to search again and display
    momentary-message about switching to literal mode.
    (isearch--momentary-message): Add optional arg SECONDS.
---
 lisp/char-fold.el |  6 +-----
 lisp/isearch.el   | 12 ++++++++----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/lisp/char-fold.el b/lisp/char-fold.el
index f8a3039..5a3c20c 100644
--- a/lisp/char-fold.el
+++ b/lisp/char-fold.el
@@ -370,11 +370,7 @@ from which to start."
       (setq i (1+ i)))
     (when (> spaces 0)
       (push (char-fold--make-space-string spaces) out))
-    (let ((regexp (apply #'concat (nreverse out))))
-      ;; Limited by `MAX_BUF_SIZE' in `regex-emacs.c'.
-      (if (> (length regexp) 5000)
-          (regexp-quote string)
-        regexp))))
+    (apply #'concat (nreverse out))))
 
 
 ;;; Commands provided for completeness.
diff --git a/lisp/isearch.el b/lisp/isearch.el
index ddf9190..7625ec1 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -2011,15 +2011,16 @@ Turning on character-folding turns off regexp mode.")
 (defvar isearch-message-properties minibuffer-prompt-properties
   "Text properties that are added to the isearch prompt.")
 
-(defun isearch--momentary-message (string)
-  "Print STRING at the end of the isearch prompt for 1 second."
+(defun isearch--momentary-message (string &optional seconds)
+  "Print STRING at the end of the isearch prompt for 1 second.
+The optional argument SECONDS overrides the number of seconds."
   (let ((message-log-max nil))
     (message "%s%s%s"
              (isearch-message-prefix nil isearch-nonincremental)
              isearch-message
              (apply #'propertize (format " [%s]" string)
                     isearch-message-properties)))
-  (sit-for 1))
+  (sit-for (or seconds 1)))
 
 (isearch-define-mode-toggle lax-whitespace " " nil
   "In ordinary search, toggles the value of the variable
@@ -3443,7 +3444,10 @@ Optional third argument, if t, means if fail just return 
nil (no error).
            (string-match "\\`Regular expression too big" isearch-error))
        (cond
        (isearch-regexp-function
-        (setq isearch-error "Too many words"))
+         (setq isearch-error nil)
+         (setq isearch-regexp-function nil)
+         (isearch-search-and-update)
+         (isearch--momentary-message "Too many words; switched to literal 
mode" 2))
        ((and isearch-lax-whitespace search-whitespace-regexp)
         (setq isearch-error "Too many spaces for whitespace matching"))))))