bug#35802: Broken data loaded from uni-decomposition

[Noam Postavsky]

> --- a/lisp/char-fold.el
> +++ b/lisp/char-fold.el
> @@ -28,7 +28,6 @@
>    (defun char-fold-make-table ()
>      (let* ((equiv (make-char-table 'char-fold-table))
>             (equiv-multi (make-char-table 'char-fold-table))
> -           (search-spaces-regexp nil)   ; workaround for bug#35802

Ah, I guess this part explains why search-spaces-regexp turned up nil in
the debugger backtrace.  So I think adjusting isearch-search-fun-default
should be enough to fix this.

>From 4f643ac01ff133e4ad088606c7faf03d2c6287b6 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Fri, 21 Jun 2019 07:09:44 -0400
Subject: [PATCH] Don't bind search-spaces-regexp around possible autoload
 (Bug#35802)

* lisp/isearch.el (isearch-search-fun-default): Move possible autoload
trigger outside let-binding of search-spaces-regexp.
* lisp/char-fold.el (char-fold-make-table): Remove no longer needed
workaround.
---
 lisp/char-fold.el |  1 -
 lisp/isearch.el   | 38 ++++++++++++++++++++++----------------
 2 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/lisp/char-fold.el b/lisp/char-fold.el
index 7a79873873..7b0e55bb11 100644
--- a/lisp/char-fold.el
+++ b/lisp/char-fold.el
@@ -28,7 +28,6 @@ (eval-and-compile
   (defun char-fold-make-table ()
     (let* ((equiv (make-char-table 'char-fold-table))
            (equiv-multi (make-char-table 'char-fold-table))
-           (search-spaces-regexp nil)   ; workaround for bug#35802
            (table (unicode-property-table-internal 'decomposition)))
       (set-char-table-extra-slot equiv 0 equiv-multi)
 
diff --git a/lisp/isearch.el b/lisp/isearch.el
index bb29c2914b..bfd2e776ec 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -3263,25 +3263,31 @@ (defun isearch--lax-regexp-function-p ()
 (defun isearch-search-fun-default ()
   "Return default functions to use for the search."
   (lambda (string &optional bound noerror count)
-    ;; Use lax versions to not fail at the end of the word while
-    ;; the user adds and removes characters in the search string
-    ;; (or when using nonincremental word isearch)
-    (let ((search-spaces-regexp (when (cond
-                                       (isearch-regexp 
isearch-regexp-lax-whitespace)
-                                       (t isearch-lax-whitespace))
+    (let (;; Evaluate this before binding `search-spaces-regexp' which
+          ;; can break all sorts of regexp searches.  In particular,
+          ;; calling `isearch-regexp-function' can trigger autoloading
+          ;; (Bug#35802).
+          (regexp
+           (cond (isearch-regexp-function
+                  (let ((lax (and (not bound)
+                                  (isearch--lax-regexp-function-p))))
+                    (when lax
+                      (setq isearch-adjusted t))
+                    (if (functionp isearch-regexp-function)
+                        (funcall isearch-regexp-function string lax)
+                      (word-search-regexp string lax))))
+                 (isearch-regexp string)
+                 (t (regexp-quote string))))
+          ;; Use lax versions to not fail at the end of the word while
+          ;; the user adds and removes characters in the search string
+          ;; (or when using nonincremental word isearch)
+          (search-spaces-regexp (when (if isearch-regexp
+                                          isearch-regexp-lax-whitespace
+                                        isearch-lax-whitespace)
                                   search-whitespace-regexp)))
       (funcall
        (if isearch-forward #'re-search-forward #'re-search-backward)
-       (cond (isearch-regexp-function
-              (let ((lax (and (not bound) (isearch--lax-regexp-function-p))))
-                (when lax
-                  (setq isearch-adjusted t))
-                (if (functionp isearch-regexp-function)
-                    (funcall isearch-regexp-function string lax)
-                  (word-search-regexp string lax))))
-             (isearch-regexp string)
-             (t (regexp-quote string)))
-       bound noerror count))))
+       regexp bound noerror count))))
 
 (defun isearch-search-string (string bound noerror)
   "Search for the first occurrence of STRING or its translation.
-- 
2.11.0