* lisp/replace.el (replace-regexp-lax-whitespace): New defcustom.

(replace-lax-whitespace, query-replace-regexp)
(query-replace-regexp-eval, replace-regexp): Doc fix.
(perform-replace, replace-highlight): Let-bind
isearch-lax-whitespace to replace-lax-whitespace and
isearch-regexp-lax-whitespace to replace-regexp-lax-whitespace.

* lisp/isearch.el (isearch-query-replace): Let-bind
replace-lax-whitespace to isearch-lax-whitespace and
replace-regexp-lax-whitespace to
isearch-regexp-lax-whitespace.

Fixes: debbugs:10885

lisp/ChangeLog

@@ -1,3 +1,17 @@
+2012-09-09  Juri Linkov  <juri@jurta.org>
+
+	* replace.el (replace-regexp-lax-whitespace): New defcustom.
+	(replace-lax-whitespace, query-replace-regexp)
+	(query-replace-regexp-eval, replace-regexp): Doc fix.
+	(perform-replace, replace-highlight): Let-bind
+	isearch-lax-whitespace to replace-lax-whitespace and
+	isearch-regexp-lax-whitespace to replace-regexp-lax-whitespace.
+
+	* isearch.el (isearch-query-replace): Let-bind
+	replace-lax-whitespace to isearch-lax-whitespace and
+	replace-regexp-lax-whitespace to
+	isearch-regexp-lax-whitespace.  (Bug#10885)
+
 2012-09-09  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* eshell/em-unix.el (eshell/sudo): Explicitly drop return value.

lisp/isearch.el

@@ -1581,10 +1581,9 @@ way to run word replacements from Isearch is `M-s w ... M-%'."
 	;; `isearch-no-upper-case-p' in `perform-replace'
 	(search-upper-case nil)
 	(replace-lax-whitespace
-	 (and search-whitespace-regexp
-	      (if isearch-regexp
-		  isearch-regexp-lax-whitespace
-		isearch-lax-whitespace)))
+	 isearch-lax-whitespace)
+	(replace-regexp-lax-whitespace
+	 isearch-regexp-lax-whitespace)
 	;; Set `isearch-recursive-edit' to nil to prevent calling
 	;; `exit-recursive-edit' in `isearch-done' that terminates
 	;; the execution of this command when it is non-nil.

lisp/replace.el

@@ -35,7 +35,15 @@
 
 (defcustom replace-lax-whitespace nil
   "Non-nil means `query-replace' matches a sequence of whitespace chars.
-When you enter a space or spaces in the strings or regexps to be replaced,
+When you enter a space or spaces in the strings to be replaced,
+it will match any sequence matched by the regexp `search-whitespace-regexp'."
+  :type 'boolean
+  :group 'matching
+  :version "24.3")
+
+(defcustom replace-regexp-lax-whitespace nil
+  "Non-nil means `query-replace-regexp' matches a sequence of whitespace chars.
+When you enter a space or spaces in the regexps to be replaced,
 it will match any sequence matched by the regexp `search-whitespace-regexp'."
   :type 'boolean
   :group 'matching
@@ -282,7 +290,7 @@ pattern of the old text to the new text, if `case-replace' and
 all caps, or capitalized, then its replacement is upcased or
 capitalized.)
 
-If `replace-lax-whitespace' is non-nil, a space or spaces in the regexp
+If `replace-regexp-lax-whitespace' is non-nil, a space or spaces in the regexp
 to be replaced will match a sequence of whitespace chars defined by the
 regexp in `search-whitespace-regexp'.
 
@@ -362,7 +370,7 @@ minibuffer.
 Preserves case in each replacement if `case-replace' and `case-fold-search'
 are non-nil and REGEXP has no uppercase letters.
 
-If `replace-lax-whitespace' is non-nil, a space or spaces in the regexp
+If `replace-regexp-lax-whitespace' is non-nil, a space or spaces in the regexp
 to be replaced will match a sequence of whitespace chars defined by the
 regexp in `search-whitespace-regexp'.
 
@@ -499,7 +507,7 @@ and TO-STRING is also null.)"
 Preserve case in each match if `case-replace' and `case-fold-search'
 are non-nil and REGEXP has no uppercase letters.
 
-If `replace-lax-whitespace' is non-nil, a space or spaces in the regexp
+If `replace-regexp-lax-whitespace' is non-nil, a space or spaces in the regexp
 to be replaced will match a sequence of whitespace chars defined by the
 regexp in `search-whitespace-regexp'.
 
@@ -1803,9 +1811,9 @@ make, or the user didn't cancel the call."
 	      (let ((isearch-regexp regexp-flag)
 		    (isearch-word delimited-flag)
 		    (isearch-lax-whitespace
-		     (and replace-lax-whitespace (not regexp-flag)))
+		     replace-lax-whitespace)
 		    (isearch-regexp-lax-whitespace
-		     (and replace-lax-whitespace regexp-flag))
+		     replace-regexp-lax-whitespace)
 		    (isearch-case-fold-search case-fold-search)
 		    (isearch-forward t))
 		(isearch-search-fun))))
@@ -2160,9 +2168,9 @@ make, or the user didn't cancel the call."
 	    (isearch-regexp regexp-flag)
 	    (isearch-word delimited-flag)
 	    (isearch-lax-whitespace
-	     (and replace-lax-whitespace (not regexp-flag)))
+	     replace-lax-whitespace)
 	    (isearch-regexp-lax-whitespace
-	     (and replace-lax-whitespace regexp-flag))
+	     replace-regexp-lax-whitespace)
 	    (isearch-case-fold-search case-fold-search)
 	    (isearch-forward t)
 	    (isearch-error nil))