* lisp/info.el (info-index-match): New face.

(Info-index, Info-apropos-matches): Add a nested subgroup to the
main pattern and add text properties with the new face to matches
in index entries relative to the beginning of the index entry.

Fixes: debbugs:14015

3 files changed, 45 insertions, 20 deletions

diff --git a/etc/NEWS b/etc/NEWS
index a4691f7f181..1947797bd34 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -174,6 +174,12 @@ When toggling, it restores the frame's previous window configuration.
 It also has an optional frame argument, which can be used by Lisp
 callers to fit the image to a frame other than the selected frame.
 
+** Info
+
+*** New face `info-index-match' is used to highlight matches in index
+entries displayed by `Info-index-next', `Info-virtual-index' and
+`info-apropos'.
+
 ** Isearch
 
 *** `C-x 8 RET' in Isearch mode reads a character by its Unicode name
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 1c955e303fb..966bbb1367c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2013-03-23  Juri Linkov  <juri@jurta.org>
+
+        * info.el (info-index-match): New face.
+        (Info-index, Info-apropos-matches): Add a nested subgroup to the
+        main pattern and add text properties with the new face to matches
+        in index entries relative to the beginning of the index entry.
+        (Bug#14015)
+
 2013-03-21  Eric Ludlam  <zappo@gnu.org>
 
         * eieio/eieio-datadebug.el (data-debug/eieio-insert-slots):
diff --git a/lisp/info.el b/lisp/info.el
index 3586a124c14..4679b51b999 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -158,6 +158,12 @@ A header-line does not scroll with the rest of the buffer."
   "Face for Info nodes in a node header."
   :group 'info)
 
+(defface info-index-match
+  '((t :inherit match))
+  "Face used to highlight matches in an index entry."
+  :group 'info
+  :version "24.4")
+
 ;; This is a defcustom largely so that we can get the benefit
 ;; of custom-initialize-delay.  Perhaps it would work to make it a
 ;; defvar and explicitly give it a standard-value property, and
@@ -3063,15 +3069,15 @@ The next cross-reference is searched using the regexp PAT, and the next link
 is searched using the text property PROP.  Move point to the closest found position
 of either a cross-reference found by `re-search-forward' or a link found by
 `next-single-char-property-change'.  Return the new position of point, or nil."
-  (let ((pcref (save-excursion (re-search-forward pat nil t)))
+  (let ((pxref (save-excursion (re-search-forward pat nil t)))
         (plink (next-single-char-property-change (point) prop)))
     (when (and (< plink (point-max)) (not (get-char-property plink prop)))
       (setq plink (next-single-char-property-change plink prop)))
     (if (< plink (point-max))
-        (if (and pcref (<= pcref plink))
+        (if (and pxref (<= pxref plink))
             (goto-char (or (match-beginning 1) (match-beginning 0)))
           (goto-char plink))
-      (if pcref (goto-char (or (match-beginning 1) (match-beginning 0)))))))
+      (if pxref (goto-char (or (match-beginning 1) (match-beginning 0)))))))
 
 (defun Info-prev-reference-or-link (pat prop)
   "Move point to the previous pattern-based cross-reference or property-based link.
@@ -3079,15 +3085,15 @@ The previous cross-reference is searched using the regexp PAT, and the previous
 is searched using the text property PROP.  Move point to the closest found position
 of either a cross-reference found by `re-search-backward' or a link found by
 `previous-single-char-property-change'.  Return the new position of point, or nil."
-  (let ((pcref (save-excursion (re-search-backward pat nil t)))
+  (let ((pxref (save-excursion (re-search-backward pat nil t)))
         (plink (previous-single-char-property-change (point) prop)))
     (when (and (> plink (point-min)) (not (get-char-property plink prop)))
       (setq plink (previous-single-char-property-change plink prop)))
     (if (> plink (point-min))
-        (if (and pcref (>= pcref plink))
+        (if (and pxref (>= pxref plink))
             (goto-char (or (match-beginning 1) (match-beginning 0)))
           (goto-char plink))
-      (if pcref (goto-char (or (match-beginning 1) (match-beginning 0)))))))
+      (if pxref (goto-char (or (match-beginning 1) (match-beginning 0)))))))
 
 (defun Info-next-reference (&optional recur count)
   "Move cursor to the next cross-reference or menu item in the node.
@@ -3276,7 +3282,7 @@ Give an empty topic name to go to the Index node itself."
            (= (aref topic 0) ?:))
       (setq topic (substring topic 1)))
   (let ((orignode Info-current-node)
-        (pattern (format "\n\\* +\\([^\n]*%s[^\n]*\\):[ \t]+\\([^\n]*\\)\\.\\(?:[ \t\n]*(line +\\([0-9]+\\))\\)?"
+        (pattern (format "\n\\* +\\([^\n]*\\(%s\\)[^\n]*\\):[ \t]+\\([^\n]*\\)\\.\\(?:[ \t\n]*(line +\\([0-9]+\\))\\)?"
                          (regexp-quote topic)))
         node (nodes (Info-index-nodes))
         (ohist-list Info-history-list)
@@ -3295,12 +3301,14 @@ Give an empty topic name to go to the Index node itself."
               (progn
                 (goto-char (point-min))
                 (while (re-search-forward pattern nil t)
-                  (push (list (match-string-no-properties 1)
-                              (match-string-no-properties 2)
-                              Info-current-node
-                              (string-to-number (concat "0"
-                                                        (match-string 3))))
-                        matches))
+                  (let ((entry (match-string-no-properties 1))
+                        (nodename (match-string-no-properties 3))
+                        (line (string-to-number (concat "0" (match-string 4)))))
+                    (add-text-properties
+                     (- (match-beginning 2) (match-beginning 1))
+                     (- (match-end 2) (match-beginning 1))
+                     '(face info-index-match) entry)
+                    (push (list entry nodename Info-current-node line) matches)))
                 (setq nodes (cdr nodes) node (car nodes)))
             (Info-goto-node node))
           (or matches
@@ -3526,7 +3534,7 @@ MATCHES is a list of index matches found by `Info-apropos-matches'.")
 Return a list of matches where each element is in the format
 \((FILENAME INDEXTEXT NODENAME LINENUMBER))."
   (unless (string= string "")
-    (let ((pattern (format "\n\\* +\\([^\n]*%s[^\n]*\\):[ \t]+\\([^\n]+\\)\\.\\(?:[ \t\n]*(line +\\([0-9]+\\))\\)?"
+    (let ((pattern (format "\n\\* +\\([^\n]*\\(%s\\)[^\n]*\\):[ \t]+\\([^\n]+\\)\\.\\(?:[ \t\n]*(line +\\([0-9]+\\))\\)?"
                            (regexp-quote string)))
           (ohist Info-history)
           (ohist-list Info-history-list)
@@ -3559,12 +3567,15 @@ Return a list of matches where each element is in the format
                         (progn
                           (goto-char (point-min))
                           (while (re-search-forward pattern nil t)
-                            (setq matches
-                                  (cons (list manual
-                                              (match-string-no-properties 1)
-                                              (match-string-no-properties 2)
-                                              (match-string-no-properties 3))
-                                        matches)))
+                            (let ((entry (match-string-no-properties 1))
+                                  (nodename (match-string-no-properties 3))
+                                  (line (match-string-no-properties 4)))
+                              (add-text-properties
+                               (- (match-beginning 2) (match-beginning 1))
+                               (- (match-end 2) (match-beginning 1))
+                               '(face info-index-match) entry)
+                              (setq matches (cons (list manual entry nodename line)
+                                                  matches))))
                           (setq nodes (cdr nodes) node (car nodes)))
                       (Info-goto-node node))))
             (error