Shell completion for filenames from current directory, related docs.

* lisp/shell.el  Shell completion now matches executable filenames from
	the current buffer's directory, on systems in which this behaviour
	is the default (windows-nt, ms-dos).
	* src/callproc.c (Vexec_path): Document that exec-directory is in it.
	* doc/emacs/mini.texi (Completion Options): Add a link to Shell Options.
	* doc/emacs/misc.texi (Shell Mode): Move documentation of
	shell-completion-fignore from Shell Mode to Shell Options.

Fixes: debbugs:15461

doc/emacs/ChangeLog

@@ -1,3 +1,9 @@
+2013-12-27  Jarek Czekalski  <jarekczek@poczta.onet.pl>
+
+	* mini.texi (Completion Options): Add a link to Shell Options.
+	* misc.texi (Shell Mode): Move documentation of
+	shell-completion-fignore from Shell Mode to Shell Options.
+
 2013-12-26  João Távora <joaotavora@gmail.com>
 	* emacs.texi (Matching): Describe new features of Electric Pair
 	mode.

doc/emacs/mini.texi

@@ -550,6 +550,9 @@ previous example, @samp{foo.e} completes to @samp{foo.elc}.  Emacs
 disregards @code{completion-ignored-extensions} when showing
 completion alternatives in the completion list.
 
+  Shell completion is an extended version of filename completion,
+@pxref{Shell Options}.
+
 @vindex completion-auto-help
   If @code{completion-auto-help} is set to @code{nil}, the completion
 commands never display the completion list buffer; you must type

doc/emacs/misc.texi

@@ -677,20 +677,13 @@ in the shell buffer to submit the current line as input.
 @item @key{TAB}
 @kindex TAB @r{(Shell mode)}
 @findex completion-at-point
+@cindex shell completion
 Complete the command name or file name before point in the shell
 buffer (@code{completion-at-point}).  This uses the usual Emacs
 completion rules (@pxref{Completion}), with the completion
 alternatives being file names, environment variable names, the shell
 command history, and history references (@pxref{History References}).
-
-@vindex shell-completion-fignore
-@vindex comint-completion-fignore
-The variable @code{shell-completion-fignore} specifies a list of file
-name extensions to ignore in Shell mode completion.  The default
-setting is @code{nil}, but some users prefer @code{("~" "#" "%")} to
-ignore file names ending in @samp{~}, @samp{#} or @samp{%}.  Other
-related Comint modes use the variable @code{comint-completion-fignore}
-instead.
+For options controlling the completion, @pxref{Shell Options}.
 
 @item M-?
 @kindex M-? @r{(Shell mode)}
@@ -1179,6 +1172,20 @@ the possible completions whenever completion is not exact.
 If you set @code{shell-completion-execonly} to @code{nil},
 it considers nonexecutable files as well.
 
+@vindex shell-completion-fignore
+@vindex comint-completion-fignore
+The variable @code{shell-completion-fignore} specifies a list of file
+name extensions to ignore in Shell mode completion.  The default
+setting is @code{nil}, but some users prefer @code{("~" "#" "%")} to
+ignore file names ending in @samp{~}, @samp{#} or @samp{%}.  Other
+related Comint modes use the variable @code{comint-completion-fignore}
+instead.
+
+@findex shell-dynamic-complete-command
+Some implementation details of the shell command completion may also be found
+in the lisp documentation of the @code{shell-dynamic-complete-command}
+function.
+
 @findex shell-pushd-tohome
 @findex shell-pushd-dextract
 @findex shell-pushd-dunique

lisp/ChangeLog

@@ -1,3 +1,9 @@
+2013-12-27  Jarek Czekalski  <jarekczek@poczta.onet.pl>
+
+	* shell.el  Shell completion now matches executable filenames from
+	the current buffer's directory, on systems in which this behaviour
+	is the default (windows-nt, ms-dos).
+
 2013-12-27  Glenn Morris  <rgm@gnu.org>
 
 	* emacs-lisp/lisp-mode.el (lisp-mode-variables): Unbreak bootstrap.

lisp/shell.el

@@ -1108,12 +1108,13 @@ See `shell-command-regexp'."
 (defun shell-dynamic-complete-command ()
   "Dynamically complete the command at point.
 This function is similar to `comint-dynamic-complete-filename', except that it
-searches `exec-path' (minus the trailing Emacs library path) for completion
+searches `exec-path' (minus trailing `exec-directory') for completion
 candidates.  Note that this may not be the same as the shell's idea of the
 path.
 
-Completion is dependent on the value of `shell-completion-execonly', plus
-those that effect file completion.
+Completion is dependent on the value of `shell-completion-execonly',
+`shell-completion-fignore', plus those that affect file completion.  See Info
+node `Shell Options'.
 
 Returns t if successful."
   (interactive)
@@ -1138,7 +1139,9 @@ Returns t if successful."
          (start (if (zerop (length filename)) (point) (match-beginning 0)))
          (end (if (zerop (length filename)) (point) (match-end 0)))
 	 (filenondir (file-name-nondirectory filename))
-	 (path-dirs (cdr (reverse exec-path))) ;FIXME: Why `cdr'?
+	 ; why cdr? see `shell-dynamic-complete-command'
+	 (path-dirs (append (cdr (reverse exec-path))
+	   (if (memq system-type '(windows-nt ms-dos)) '("."))))
 	 (cwd (file-name-as-directory (expand-file-name default-directory)))
 	 (ignored-extensions
 	  (and comint-completion-fignore

src/ChangeLog

@@ -1,3 +1,7 @@
+2013-12-27  Jarek Czekalski  <jarekczek@poczta.onet.pl>
+
+	* callproc.c (Vexec_path): Document that exec-directory is in it.
+
 2013-12-27  Steve Purcell  <steve@sanityinc.com>  (tiny change)
 
 	* nsterm.m (syms_of_nsterm): Enable ns-use-srgb-colorspace by

src/callproc.c

@@ -1686,7 +1686,11 @@ default if SHELL is not set.  */);
 
   DEFVAR_LISP ("exec-path", Vexec_path,
 	       doc: /* List of directories to search programs to run in subprocesses.
-Each element is a string (directory name) or nil (try default directory).  */);
+Each element is a string (directory name) or nil (try default directory).
+
+By default the last element of this list is `exec-directory'. The
+last element is not always used, for example in shell completion
+(`shell-dynamic-complete-command').  */);
 
   DEFVAR_LISP ("exec-suffixes", Vexec_suffixes,
 	       doc: /* List of suffixes to try to find executable file names.