Bash-4.2 Official Patch 29

[Chet Ramey]

                             BASH PATCH REPORT
                             =================

Bash-Release:   4.2
Patch-ID:       bash42-029

Bug-Reported-by:        "Michael Kalisz" <michael@kalisz.homelinux.net>
Bug-Reference-ID:       
<50241.78.69.11.112.1298585641.squirrel@kalisz.homelinux.net>
Bug-Reference-URL:      
http://lists.gnu.org/archive/html/bug-bash/2011-02/msg00274.html

Bug-Description:

Bash-4.2 tries to leave completed directory names as the user typed them,
without expanding them to a full pathname.  One effect of this is that
shell variables used in pathnames being completed (e.g., $HOME) are left
unchanged, but the `$' is quoted by readline because it is a special
character to the shell.

This patch introduces two things:

1.  A new shell option, `direxpand', which, if set, attempts to emulate the
    bash-4.1 behavior of expanding words to full pathnames during
    completion;
2.  A set of heuristics that reduce the number of times special characters
    such as `$' are quoted when the directory name is not expanded.

Patch (apply with `patch -p0'):

diff -NrC 2 ../bash-4.2-patched/bashline.c ./bashline.c
*** ../bash-4.2-patched/bashline.c      2011-01-16 15:32:47.000000000 -0500
--- ./bashline.c        2012-05-07 16:27:18.000000000 -0400
***************
*** 122,125 ****
--- 122,128 ----
  static int bash_push_line __P((void));
  
+ static rl_icppfunc_t *save_directory_hook __P((void));
+ static void reset_directory_hook __P((rl_icppfunc_t *));
+ 
  static void cleanup_expansion_error __P((void));
  static void maybe_make_readline_line __P((char *));
***************
*** 244,251 ****
--- 247,261 ----
  int dircomplete_spelling = 0;
  
+ /* Expand directory names during word/filename completion. */
+ int dircomplete_expand = 0;
+ int dircomplete_expand_relpath = 0;
+ 
  static char *bash_completer_word_break_characters = " \t\n\"'@><=;|&(:";
  static char *bash_nohostname_word_break_characters = " \t\n\"'><=;|&(:";
  /* )) */
  
+ static const char *default_filename_quote_characters = " 
\t\n\\\"'@<>=;|&()#$`?*[!:{~";       /*}*/
+ static char *custom_filename_quote_characters = 0;
+ 
  static rl_hook_func_t *old_rl_startup_hook = (rl_hook_func_t *)NULL;
  
***************
*** 502,506 ****
    /* Tell the completer that we might want to follow symbolic links or
       do other expansion on directory names. */
!   rl_directory_rewrite_hook = bash_directory_completion_hook;
  
    rl_filename_rewrite_hook = bash_filename_rewrite_hook;
--- 512,516 ----
    /* Tell the completer that we might want to follow symbolic links or
       do other expansion on directory names. */
!   set_directory_hook ();
  
    rl_filename_rewrite_hook = bash_filename_rewrite_hook;
***************
*** 530,534 ****
  
    /* characters that need to be quoted when appearing in filenames. */
!   rl_filename_quote_characters = " \t\n\\\"'@<>=;|&()#$`?*[!:{~";     /*}*/
  
    rl_filename_quoting_function = bash_quote_filename;
--- 540,544 ----
  
    /* characters that need to be quoted when appearing in filenames. */
!   rl_filename_quote_characters = default_filename_quote_characters;
  
    rl_filename_quoting_function = bash_quote_filename;
***************
*** 565,570 ****
    rl_attempted_completion_function = attempt_shell_completion;
    rl_completion_entry_function = NULL;
-   rl_directory_rewrite_hook = bash_directory_completion_hook;
    rl_ignore_some_completions_function = filename_completion_ignore;
  }
  
--- 575,582 ----
    rl_attempted_completion_function = attempt_shell_completion;
    rl_completion_entry_function = NULL;
    rl_ignore_some_completions_function = filename_completion_ignore;
+   rl_filename_quote_characters = default_filename_quote_characters;
+ 
+   set_directory_hook ();
  }
  
***************
*** 1280,1283 ****
--- 1292,1298 ----
    rl_ignore_some_completions_function = filename_completion_ignore;
  
+   rl_filename_quote_characters = default_filename_quote_characters;
+   set_directory_hook ();
+ 
    /* Determine if this could be a command word.  It is if it appears at
       the start of the line (ignoring preceding whitespace), or if it
***************
*** 1592,1595 ****
--- 1607,1616 ----
          else
            {
+            if (dircomplete_expand && dot_or_dotdot (filename_hint))
+               {
+                 dircomplete_expand = 0;
+                 set_directory_hook ();
+                 dircomplete_expand = 1;
+               }
              mapping_over = 4;
              goto inner;
***************
*** 1792,1795 ****
--- 1813,1819 ----
   inner:
    val = rl_filename_completion_function (filename_hint, istate);
+   if (mapping_over == 4 && dircomplete_expand)
+     set_directory_hook ();
+ 
    istate = 1;
  
***************
*** 2694,2697 ****
--- 2718,2767 ----
  }
  
+ /* Functions to save and restore the appropriate directory hook */
+ /* This is not static so the shopt code can call it */
+ void
+ set_directory_hook ()
+ {
+   if (dircomplete_expand)
+     {
+       rl_directory_completion_hook = bash_directory_completion_hook;
+       rl_directory_rewrite_hook = (rl_icppfunc_t *)0;
+     }
+   else
+     {
+       rl_directory_rewrite_hook = bash_directory_completion_hook;
+       rl_directory_completion_hook = (rl_icppfunc_t *)0;
+     }
+ }
+ 
+ static rl_icppfunc_t *
+ save_directory_hook ()
+ {
+   rl_icppfunc_t *ret;
+ 
+   if (dircomplete_expand)
+     {
+       ret = rl_directory_completion_hook;
+       rl_directory_completion_hook = (rl_icppfunc_t *)NULL;
+     }
+   else
+     {
+       ret = rl_directory_rewrite_hook;
+       rl_directory_rewrite_hook = (rl_icppfunc_t *)NULL;
+     }
+ 
+   return ret;
+ }
+ 
+ static void
+ restore_directory_hook (hookf)
+      rl_icppfunc_t *hookf;
+ {
+   if (dircomplete_expand)
+     rl_directory_completion_hook = hookf;
+   else
+     rl_directory_rewrite_hook = hookf;
+ }
+ 
  /* Handle symbolic link references and other directory name
     expansions while hacking completion.  This should return 1 if it modifies
***************
*** 2703,2720 ****
  {
    char *local_dirname, *new_dirname, *t;
!   int return_value, should_expand_dirname;
    WORD_LIST *wl;
    struct stat sb;
  
!   return_value = should_expand_dirname = 0;
    local_dirname = *dirname;
  
!   if (mbschr (local_dirname, '$'))
!     should_expand_dirname = 1;
    else
      {
        t = mbschr (local_dirname, '`');
        if (t && unclosed_pair (local_dirname, strlen (local_dirname), "`") == 
0)
!       should_expand_dirname = 1;
      }
  
--- 2773,2801 ----
  {
    char *local_dirname, *new_dirname, *t;
!   int return_value, should_expand_dirname, nextch, closer;
    WORD_LIST *wl;
    struct stat sb;
  
!   return_value = should_expand_dirname = nextch = closer = 0;
    local_dirname = *dirname;
  
!   if (t = mbschr (local_dirname, '$'))
!     {
!       should_expand_dirname = '$';
!       nextch = t[1];
!       /* Deliberately does not handle the deprecated $[...] arithmetic
!        expansion syntax */
!       if (nextch == '(')
!       closer = ')';
!       else if (nextch == '{')
!       closer = '}';
!       else
!       nextch = 0;
!     }
    else
      {
        t = mbschr (local_dirname, '`');
        if (t && unclosed_pair (local_dirname, strlen (local_dirname), "`") == 
0)
!       should_expand_dirname = '`';
      }
  
***************
*** 2740,2743 ****
--- 2821,2841 ----
          dispose_words (wl);
          local_dirname = *dirname;
+         /* XXX - change rl_filename_quote_characters here based on
+            should_expand_dirname/nextch/closer.  This is the only place
+            custom_filename_quote_characters is modified. */
+         if (rl_filename_quote_characters && *rl_filename_quote_characters)
+           {
+             int i, j, c;
+             i = strlen (default_filename_quote_characters);
+             custom_filename_quote_characters = xrealloc 
(custom_filename_quote_characters, i+1);
+             for (i = j = 0; c = default_filename_quote_characters[i]; i++)
+               {
+                 if (c == should_expand_dirname || c == nextch || c == closer)
+                   continue;
+                 custom_filename_quote_characters[j++] = c;
+               }
+             custom_filename_quote_characters[j] = '\0';
+             rl_filename_quote_characters = custom_filename_quote_characters;
+           }
        }
        else
***************
*** 2759,2762 ****
--- 2857,2871 ----
      }
  
+   /* no_symbolic_links == 0 -> use (default) logical view of the file system.
+      local_dirname[0] == '.' && local_dirname[1] == '/' means files in the
+      current directory (./).
+      local_dirname[0] == '.' && local_dirname[1] == 0 means relative pathnames
+      in the current directory (e.g., lib/sh).
+      XXX - should we do spelling correction on these? */
+ 
+   /* This is test as it was in bash-4.2: skip relative pathnames in current
+      directory.  Change test to
+       (local_dirname[0] != '.' || (local_dirname[1] && local_dirname[1] != 
'/'))
+      if we want to skip paths beginning with ./ also. */
    if (no_symbolic_links == 0 && (local_dirname[0] != '.' || local_dirname[1]))
      {
***************
*** 2764,2767 ****
--- 2873,2885 ----
        int len1, len2;
  
+       /* If we have a relative path
+                       (local_dirname[0] != '/' && local_dirname[0] != '.')
+        that is canonical after appending it to the current directory, then
+               temp1 = temp2+'/'
+        That is,
+               strcmp (temp1, temp2) == 0
+        after adding a slash to temp2 below.  It should be safe to not
+        change those.
+       */
        t = get_working_directory ("symlink-hook");
        temp1 = make_absolute (local_dirname, t);
***************
*** 2798,2802 ****
            }
        }
!       return_value |= STREQ (local_dirname, temp2) == 0;
        free (local_dirname);
        *dirname = temp2;
--- 2916,2928 ----
            }
        }
! 
!       /* dircomplete_expand_relpath == 0 means we want to leave relative
!        pathnames that are unchanged by canonicalization alone.
!        *local_dirname != '/' && *local_dirname != '.' == relative pathname
!        (consistent with general.c:absolute_pathname())
!        temp1 == temp2 (after appending a slash to temp2) means the pathname
!        is not changed by canonicalization as described above. */
!       if (dircomplete_expand_relpath || ((local_dirname[0] != '/' && 
local_dirname[0] != '.') && STREQ (temp1, temp2) == 0))
!       return_value |= STREQ (local_dirname, temp2) == 0;
        free (local_dirname);
        *dirname = temp2;
***************
*** 3003,3012 ****
    orig_func = rl_completion_entry_function;
    orig_attempt_func = rl_attempted_completion_function;
-   orig_dir_func = rl_directory_rewrite_hook;
    orig_ignore_func = rl_ignore_some_completions_function;
    orig_rl_completer_word_break_characters = 
rl_completer_word_break_characters;
    rl_completion_entry_function = rl_filename_completion_function;
    rl_attempted_completion_function = (rl_completion_func_t *)NULL;
-   rl_directory_rewrite_hook = (rl_icppfunc_t *)NULL;
    rl_ignore_some_completions_function = filename_completion_ignore;
    rl_completer_word_break_characters = " \t\n\"\'";
--- 3129,3139 ----
    orig_func = rl_completion_entry_function;
    orig_attempt_func = rl_attempted_completion_function;
    orig_ignore_func = rl_ignore_some_completions_function;
    orig_rl_completer_word_break_characters = 
rl_completer_word_break_characters;
+ 
+   orig_dir_func = save_directory_hook ();
+ 
    rl_completion_entry_function = rl_filename_completion_function;
    rl_attempted_completion_function = (rl_completion_func_t *)NULL;
    rl_ignore_some_completions_function = filename_completion_ignore;
    rl_completer_word_break_characters = " \t\n\"\'";
***************
*** 3016,3023 ****
    rl_completion_entry_function = orig_func;
    rl_attempted_completion_function = orig_attempt_func;
-   rl_directory_rewrite_hook = orig_dir_func;
    rl_ignore_some_completions_function = orig_ignore_func;
    rl_completer_word_break_characters = 
orig_rl_completer_word_break_characters;
  
    return r;
  }
--- 3143,3151 ----
    rl_completion_entry_function = orig_func;
    rl_attempted_completion_function = orig_attempt_func;
    rl_ignore_some_completions_function = orig_ignore_func;
    rl_completer_word_break_characters = 
orig_rl_completer_word_break_characters;
  
+   restore_directory_hook (orig_dir_func);
+ 
    return r;
  }
diff -NrC 2 ../bash-4.2-patched/bashline.h ./bashline.h
*** ../bash-4.2-patched/bashline.h      2009-01-04 14:32:22.000000000 -0500
--- ./bashline.h        2012-05-07 16:27:18.000000000 -0400
***************
*** 34,41 ****
--- 34,46 ----
  extern int bash_re_edit __P((char *));
  
+ extern void bashline_set_event_hook __P((void));
+ extern void bashline_reset_event_hook __P((void));
+ 
  extern int bind_keyseq_to_unix_command __P((char *));
  
  extern char **bash_default_completion __P((const char *, int, int, int, int));
  
+ void set_directory_hook __P((void));
+ 
  /* Used by programmable completion code. */
  extern char *command_word_completion_function __P((const char *, int));
diff -NrC 2 ../bash-4.2-patched/builtins/shopt.def ./builtins/shopt.def
*** ../bash-4.2-patched/builtins/shopt.def      2010-07-02 22:42:44.000000000 
-0400
--- ./builtins/shopt.def        2012-05-07 16:27:18.000000000 -0400
***************
*** 62,65 ****
--- 62,69 ----
  #include "bashgetopt.h"
  
+ #if defined (READLINE)
+ #  include "../bashline.h"
+ #endif
+ 
  #if defined (HISTORY)
  #  include "../bashhist.h"
***************
*** 95,99 ****
  extern int no_empty_command_completion;
  extern int force_fignore;
! extern int dircomplete_spelling;
  
  extern int enable_hostname_completion __P((int));
--- 99,103 ----
  extern int no_empty_command_completion;
  extern int force_fignore;
! extern int dircomplete_spelling, dircomplete_expand;
  
  extern int enable_hostname_completion __P((int));
***************
*** 122,125 ****
--- 126,133 ----
  #endif
  
+ #if defined (READLINE)
+ static int shopt_set_complete_direxpand __P((char *, int));
+ #endif
+ 
  static int shopt_login_shell;
  static int shopt_compat31;
***************
*** 151,154 ****
--- 159,163 ----
    { "compat41", &shopt_compat41, set_compatibility_level },
  #if defined (READLINE)
+   { "direxpand", &dircomplete_expand, shopt_set_complete_direxpand },
    { "dirspell", &dircomplete_spelling, (shopt_set_func_t *)NULL },
  #endif
***************
*** 536,539 ****
--- 545,559 ----
  }
  
+ #if defined (READLINE)
+ static int
+ shopt_set_complete_direxpand (option_name, mode)
+      char *option_name;
+      int mode;
+ {
+   set_directory_hook ();
+   return 0;
+ }
+ #endif
+ 
  #if defined (RESTRICTED_SHELL)
  /* Don't allow the value of restricted_shell to be modified. */
Binary files ../bash-4.2-patched/doc/._bashref.pdf and ./doc/._bashref.pdf 
differ
diff -NrC 2 ../bash-4.2-patched/doc/bash.1 ./doc/bash.1
*** ../bash-4.2-patched/doc/bash.1      2011-01-16 15:31:39.000000000 -0500
--- ./doc/bash.1        2012-05-07 16:27:18.000000000 -0400
***************
*** 8949,8952 ****
--- 8949,8962 ----
  The default bash behavior remains as in previous versions.
  .TP 8
+ .B direxpand
+ If set,
+ .B bash
+ replaces directory names with the results of word expansion when performing
+ filename completion.  This changes the contents of the readline editing
+ buffer.
+ If not set,
+ .B bash
+ attempts to preserve what the user typed.
+ .TP 8
  .B dirspell
  If set,
diff -NrC 2 ../bash-4.2-patched/doc/bashref.texi ./doc/bashref.texi
*** ../bash-4.2-patched/doc/bashref.texi        2011-01-16 15:31:57.000000000 
-0500
--- ./doc/bashref.texi  2012-05-07 16:27:18.000000000 -0400
***************
*** 4536,4539 ****
--- 4536,4546 ----
  The default Bash behavior remains as in previous versions.
  
+ @item direxpand
+ If set, Bash
+ replaces directory names with the results of word expansion when performing
+ filename completion.  This changes the contents of the readline editing
+ buffer.
+ If not set, Bash attempts to preserve what the user typed.
+ 
  @item dirspell
  If set, Bash
diff -NrC 2 ../bash-4.2-patched/tests/shopt.right ./tests/shopt.right
*** ../bash-4.2-patched/tests/shopt.right       2010-07-02 23:36:30.000000000 
-0400
--- ./tests/shopt.right 2012-05-07 16:27:18.000000000 -0400
***************
*** 13,16 ****
--- 13,17 ----
  shopt -u compat40
  shopt -u compat41
+ shopt -u direxpand
  shopt -u dirspell
  shopt -u dotglob
***************
*** 69,72 ****
--- 70,74 ----
  shopt -u compat40
  shopt -u compat41
+ shopt -u direxpand
  shopt -u dirspell
  shopt -u dotglob
***************
*** 102,105 ****
--- 104,108 ----
  compat40              off
  compat41              off
+ direxpand             off
  dirspell              off
  dotglob               off
*** ../bash-4.2-patched/patchlevel.h    Sat Jun 12 20:14:48 2010
--- patchlevel.h        Thu Feb 24 21:41:34 2011
***************
*** 26,30 ****
     looks for to find the patch level (for the sccs version string). */
  
! #define PATCHLEVEL 28
  
  #endif /* _PATCHLEVEL_H_ */
--- 26,30 ----
     looks for to find the patch level (for the sccs version string). */
  
! #define PATCHLEVEL 29
  
  #endif /* _PATCHLEVEL_H_ */

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/