bug#14111: [patch] handle function names with a single char in imenu in sh-mode

[Masatake YAMATO]

This report includes a patch fixing a bug. 
Please, review and install it to the official tree if appreciated.

The patch from two parts:

    1. fixing imenu expression for sh-mode.
    2. A test case

Description of bug:
Imenu in sh-mode cannot capture "a" in following buffer:

      a()
      {
      }

`sh-imenu-generic-expression' expects function names consist
of more than 2 characters.

------------------------------------------------------------
revno: 112200
committer: Masatake YAMATO <yamato@redhat.com>
branch nick: emacs-sh-add-log
timestamp: Mon 2013-04-01 16:41:48 +0900
message:
  * lisp/progmodes/sh-script.el (sh-imenu-generic-expression): Handle
  function names with a single character.
  
  * automated/imenu-tests.el: New file.
diff:
=== modified file 'lisp/ChangeLog'
--- lisp/ChangeLog      2013-03-30 19:31:27 +0000
+++ lisp/ChangeLog      2013-04-01 07:41:48 +0000
@@ -1,3 +1,8 @@
+2013-04-01  Masatake YAMATO  <yamato@localhost.localdomain>
+
+       * progmodes/sh-script.el (sh-imenu-generic-expression): Handle
+       function names with a single character.
+
 2013-03-30  Fabián Ezequiel Gallina  <fabian@anue.biz>
 
        Un-indent after "pass" and "return" statements (Bug#13888)

=== modified file 'lisp/progmodes/sh-script.el'
--- lisp/progmodes/sh-script.el 2013-03-05 17:13:01 +0000
+++ lisp/progmodes/sh-script.el 2013-04-01 07:41:48 +0000
@@ -335,11 +335,11 @@
      . ((nil
         ;; function FOO
         ;; function FOO()
-         "^\\s-*function\\s-+\\\([[:alpha:]_][[:alnum:]_]+\\)\\s-*\\(?:()\\)?"
+         "^\\s-*function\\s-+\\\([[:alpha:]_][[:alnum:]_]*\\)\\s-*\\(?:()\\)?"
          1)
        ;; FOO()
        (nil
-        "^\\s-*\\([[:alpha:]_][[:alnum:]_]+\\)\\s-*()"
+        "^\\s-*\\([[:alpha:]_][[:alnum:]_]*\\)\\s-*()"
         1)
        )))
   "Alist of regular expressions for recognizing shell function definitions.

=== modified file 'test/ChangeLog'
--- test/ChangeLog      2013-03-30 16:55:47 +0000
+++ test/ChangeLog      2013-04-01 07:41:48 +0000
@@ -1,3 +1,7 @@
+2013-04-01  Masatake YAMATO  <yamato@redhat.com>
+
+       * automated/imenu-tests.el: New file.
+
 2013-03-30  Fabián Ezequiel Gallina  <fabian@anue.biz>
 
        * automated/python-tests.el (python-indent-block-enders): New test.

=== added file 'test/automated/imenu-tests.el'
--- test/automated/imenu-tests.el       1970-01-01 00:00:00 +0000
+++ test/automated/imenu-tests.el       2013-04-01 07:41:48 +0000
@@ -0,0 +1,87 @@
+;;; imenu-tests.el --- Test suite for imenu.
+
+;; Copyright (C) 2013 Free Software Foundation, Inc.
+
+;; Author: Masatake YAMATO <yamato@redhat.com>
+;; Keywords: tools convenience
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'imenu)
+
+;; (imenu-simple-scan-deftest-gather-strings-from-list
+;;     '(nil t 'a (0 . "x") ("c" . "d") ("a" 0 "b") ))
+;; => ("b" "a" "d" "c" "x")
+(defun imenu-simple-scan-deftest-gather-strings-from-list(input)
+  "Gather strings from INPUT, a list."
+  (let ((result ()))
+    (while input
+      (cond
+       ((stringp input)
+       (setq result (cons input result)
+             input nil))
+       ((atom input)
+       (setq input nil))
+       ((listp (car input))
+       (setq result (append
+                     (imenu-simple-scan-deftest-gather-strings-from-list (car 
input))
+                     result)
+             input (cdr input)))
+       ((stringp (car input))
+       (setq result (cons (car input) result)
+             input (cdr input)))
+       (t
+       (setq input (cdr input)))))
+    result))
+
+(defmacro imenu-simple-scan-deftest (name doc major-mode content 
expected-items)
+  "Generate an ert test for mode-own imenu expression.
+Run `imenu-create-index-function' at the buffer which content is
+CONTENT with MAJOR-MODE. A generated test runs `imenu-create-index-function'
+at the buffer which content is CONTENT with MAJOR-MODE. Then it compares a list
+of strings which are picked up from the result with EXPECTED-ITEMS."
+  (let ((xname (intern (concat "imenu-simple-scan-deftest-" (symbol-name 
name)))))
+    `(ert-deftest ,xname ()
+        ,doc
+       (with-temp-buffer
+        (insert ,content)
+        (funcall ',major-mode)
+        (let ((result-items (sort 
(imenu-simple-scan-deftest-gather-strings-from-list
+                                   (funcall imenu-create-index-function))
+                                  #'string-lessp))
+              (expected-items (sort (copy-sequence ,expected-items) 
#'string-lessp)))
+          (should (equal result-items expected-items))
+          )))))
+
+(imenu-simple-scan-deftest sh "Test imenu expression for sh-mode." sh-mode "a()
+{
+}
+function b
+{
+}
+function c()
+{
+}
+function ABC_D()
+{
+}
+" '("a" "b" "c" "ABC_D"))
+
+(provide 'imenu-tests)
+
+;;; imenu-tests.el ends here