Update the description of version handling.

[gnu-emacs] / lisp / dabbrev.el

diff --git a/lisp/dabbrev.el b/lisp/dabbrev.el
index 55b080ee0b15697916f9aec19a25ee5c6b798835..fd8b596d5301ed58cc9ddbdbe66e86b1d86e6359 100644 (file)
--- a/lisp/dabbrev.el
+++ b/lisp/dabbrev.el
@@ -147,23 +147,41 @@ Any other non-nil version means case is not significant."
 
 (defcustom dabbrev-upcase-means-case-search nil
   "*The significance of an uppercase character in an abbreviation.
-nil means case fold search, non-nil means case sensitive search.
+nil means case fold search when searching for possible expansions;
+non-nil means case sensitive search.
 
 This variable has an effect only when the value of
 `dabbrev-case-fold-search' says to ignore case."
   :type 'boolean
   :group 'dabbrev)
 
+(defcustom dabbrev-case-distinction 'case-replace
+  "*Whether dabbrev treats expansions as the same if they differ in case.
+
+A value of nil means treat them as different.
+A value of `case-replace' means distinguish them if `case-replace' is nil.
+Any other non-nil value means to treat them as the same.
+
+This variable has an effect only when the value of
+`dabbrev-case-fold-search' specifies to ignore case."
+  :type '(choice (const :tag "off" nil)
+                (const :tag "based on `case-replace'" case-replace)
+                (other :tag "on" t))
+  :group 'dabbrev
+  :version "21.4")
+
 (defcustom dabbrev-case-replace 'case-replace
-  "*Controls whether dabbrev preserves case when expanding the abbreviation.
-A value of nil means preserve case.
-A value of `case-replace' means preserve case if `case-replace' is nil.
-Any other non-nil version means do not preserve case.
+  "*Whether dabbrev applies the abbreviations's case pattern to the expansion.
+
+A value of nil means preserve the expansion's case pattern.
+A value of `case-replace' means preserve it if `case-replace' is nil.
+Any other non-nil value means modify the expansion
+by applying the abbreviation's case pattern to it.
 
 This variable has an effect only when the value of
 `dabbrev-case-fold-search' specifies to ignore case."
   :type '(choice (const :tag "off" nil)
-                (const :tag "like M-x query-replace" case-replace)
+                (const :tag "based on `case-replace'" case-replace)
                 (other :tag "on" t))
   :group 'dabbrev)
 
@@ -689,7 +707,11 @@ of the expansion in `dabbrev--last-expansion-location'."
          (while (and (> count 0)
                      (setq expansion (dabbrev--search abbrev
                                                       reverse
-                                                      ignore-case)))
+                                                      (and ignore-case
+                                                           (if (eq dabbrev-case-distinction 'case-replace)
+                                                               case-replace
+                                                             dabbrev-case-distinction))
+                                                      )))
            (setq count (1- count))))
        (and expansion
             (setq dabbrev--last-expansion-location (point)))
@@ -904,10 +926,14 @@ to record whether we upcased the expansion, downcased it, or did neither."
                    (cond ((equal abbrev (upcase abbrev)) 'upcase)
                          ((equal abbrev (downcase abbrev)) 'downcase)))))
 
-    ;; Convert newlines to spaces.
+    ;; Convert whitespace to single spaces.
     (if dabbrev--eliminate-newlines
-       (while (string-match "\n" expansion)
-         (setq expansion (replace-match " " nil nil expansion))))
+       ;; Start searching at end of ABBREV so that any whitespace
+       ;; carried over from the existing text is not changed.
+       (let ((pos (length abbrev)))
+         (while (string-match "[\n \t]+" expansion pos)
+           (setq pos (1+ (match-beginning 0)))
+           (setq expansion (replace-match " " nil nil expansion)))))
 
     (if old
        (save-excursion
@@ -950,7 +976,10 @@ Leaves point at the location of the start of the expansion."
                            "\\(" dabbrev--abbrev-char-regexp "\\)"))
          (pattern2 (concat (regexp-quote abbrev)
                           "\\(\\(" dabbrev--abbrev-char-regexp "\\)+\\)"))
-         (found-string nil))
+         ;; This makes it possible to find matches in minibuffer prompts
+         ;; even when they are "inviolable".
+         (inhibit-point-motion-hooks t)
+         found-string result)
       ;; Limited search.
       (save-restriction
        (and dabbrev-limit
@@ -974,7 +1003,8 @@ Leaves point at the location of the start of the expansion."
            ;; We have a truly valid match.  Find the end.
            (re-search-forward pattern2)
            (setq found-string (buffer-substring-no-properties
-                               (match-beginning 1) (match-end 1)))
+                               (match-beginning 0) (match-end 0)))
+           (setq result found-string)
            (and ignore-case (setq found-string (downcase found-string)))
            ;; Ignore this match if it's already in the table.
            (if (dabbrev-filter-elements
@@ -986,16 +1016,12 @@ Leaves point at the location of the start of the expansion."
              (goto-char (match-beginning 0))
            (goto-char (match-end 0))))
        ;; If we found something, use it.
-       (if found-string
-           ;; Put it into `dabbrev--last-table'
-           ;; and return it (either downcased, or as is).
-           (let ((result (buffer-substring-no-properties
-                          (match-beginning 0) (match-end 0))))
-             (setq dabbrev--last-table
-                   (cons found-string dabbrev--last-table))
-             (if (and ignore-case (eval dabbrev-case-replace))
-                 result
-               result)))))))
+       (when found-string
+         ;; Put it into `dabbrev--last-table'
+         ;; and return it (either downcased, or as is).
+         (setq dabbrev--last-table
+               (cons found-string dabbrev--last-table))
+         result)))))
 
 (dolist (mess '("^No dynamic expansion for .* found$"
                "^No further dynamic expansion for .* found$"