1 files changed, 117 insertions, 109 deletions

diff --git a/src/dired.c b/src/dired.c
index 3530b74ecb4..ab48488966b 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -1,5 +1,6 @@
 /* Lisp functions for making directory listings.
-   Copyright (C) 1985-1986, 1993-1994, 1999-2012 Free Software Foundation, Inc.
+   Copyright (C) 1985-1986, 1993-1994, 1999-2013 Free Software
+   Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -29,6 +30,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <grp.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <unistd.h>
 
 #include <dirent.h>
@@ -53,6 +55,7 @@ static Lisp_Object Qfile_attributes;
 static Lisp_Object Qfile_attributes_lessp;
 
 static ptrdiff_t scmp (const char *, const char *, ptrdiff_t);
+static Lisp_Object file_attributes (int, char const *, Lisp_Object);
 
 /* Return the number of bytes in DP's name.  */
 static ptrdiff_t
@@ -65,6 +68,44 @@ dirent_namelen (struct dirent *dp)
 #endif
 }
 
+static DIR *
+open_directory (char const *name, int *fdp)
+{
+  DIR *d;
+  int fd, opendir_errno;
+
+  block_input ();
+
+#ifdef DOS_NT
+  /* Directories cannot be opened.  The emulation assumes that any
+     file descriptor other than AT_FDCWD corresponds to the most
+     recently opened directory.  This hack is good enough for Emacs.  */
+  fd = 0;
+  d = opendir (name);
+  opendir_errno = errno;
+#else
+  fd = emacs_open (name, O_RDONLY | O_DIRECTORY, 0);
+  if (fd < 0)
+    {
+      opendir_errno = errno;
+      d = 0;
+    }
+  else
+    {
+      d = fdopendir (fd);
+      opendir_errno = errno;
+      if (! d)
+        close (fd);
+    }
+#endif
+
+  unblock_input ();
+
+  *fdp = fd;
+  errno = opendir_errno;
+  return d;
+}
+
 #ifdef WINDOWSNT
 Lisp_Object
 directory_files_internal_w32_unwind (Lisp_Object arg)
@@ -77,7 +118,7 @@ directory_files_internal_w32_unwind (Lisp_Object arg)
 static Lisp_Object
 directory_files_internal_unwind (Lisp_Object dh)
 {
-  DIR *d = (DIR *) XSAVE_VALUE (dh)->pointer;
+  DIR *d = XSAVE_POINTER (dh, 0);
   block_input ();
   closedir (d);
   unblock_input ();
@@ -95,6 +136,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
                           Lisp_Object id_format)
 {
   DIR *d;
+  int fd;
   ptrdiff_t directory_nbytes;
   Lisp_Object list, dirfilename, encoded_directory;
   struct re_pattern_buffer *bufp = NULL;
@@ -141,9 +183,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
   /* Now *bufp is the compiled form of MATCH; don't call anything
      which might compile a new regexp until we're done with the loop!  */
 
-  block_input ();
-  d = opendir (SSDATA (dirfilename));
-  unblock_input ();
+  d = open_directory (SSDATA (dirfilename), &fd);
   if (d == NULL)
     report_file_error ("Opening directory", Fcons (directory, Qnil));
 
@@ -151,7 +191,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
      file-attributes on filenames, both of which can throw, so we must
      do a proper unwind-protect.  */
   record_unwind_protect (directory_files_internal_unwind,
-                         make_save_value (d, 0));
+                         make_save_pointer (d));
 
 #ifdef WINDOWSNT
   if (attrs)
@@ -193,19 +233,15 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
 
       errno = 0;
       dp = readdir (d);
-
-      if (dp == NULL && (0
-#ifdef EAGAIN
-                         || errno == EAGAIN
-#endif
-#ifdef EINTR
-                         || errno == EINTR
-#endif
-                         ))
-        { QUIT; continue; }
-
-      if (dp == NULL)
-        break;
+      if (!dp)
+        {
+          if (errno == EAGAIN || errno == EINTR)
+            {
+              QUIT;
+              continue;
+            }
+          break;
+        }
 
       len = dirent_namelen (dp);
       name = finalname = make_unibyte_string (dp->d_name, len);
@@ -222,7 +258,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
       QUIT;
 
       if (NILP (match)
-          || (0 <= re_search (bufp, SSDATA (name), len, 0, len, 0)))
+          || re_search (bufp, SSDATA (name), len, 0, len, 0) >= 0)
         wanted = 1;
 
       immediate_quit = 0;
@@ -262,20 +298,9 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
 
           if (attrs)
             {
-              /* Construct an expanded filename for the directory entry.
-                 Use the decoded names for input to Ffile_attributes.  */
-              Lisp_Object decoded_fullname, fileattrs;
-              struct gcpro gcpro1, gcpro2;
-
-              decoded_fullname = fileattrs = Qnil;
-              GCPRO2 (decoded_fullname, fileattrs);
-
-              /* Both Fexpand_file_name and Ffile_attributes can GC.  */
-              decoded_fullname = Fexpand_file_name (name, directory);
-              fileattrs = Ffile_attributes (decoded_fullname, id_format);
-
+              Lisp_Object fileattrs
+                = file_attributes (fd, dp->d_name, id_format);
               list = Fcons (Fcons (finalname, fileattrs), list);
-              UNGCPRO;
             }
           else
             list = Fcons (finalname, list);
@@ -416,8 +441,7 @@ These are all file names in directory DIRECTORY which begin with FILE.  */)
   return file_name_completion (file, directory, 1, Qnil);
 }
 
-static int file_name_completion_stat (Lisp_Object dirname, struct dirent *dp,
-                                      struct stat *st_addr);
+static int file_name_completion_stat (int, struct dirent *, struct stat *);
 static Lisp_Object Qdefault_directory;
 
 static Lisp_Object
@@ -425,6 +449,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
                       Lisp_Object predicate)
 {
   DIR *d;
+  int fd;
   ptrdiff_t bestmatchsize = 0;
   int matchcount = 0;
   /* If ALL_FLAG is 1, BESTMATCH is the list of all matches, decoded.
@@ -459,16 +484,14 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
      on the encoded file name.  */
   encoded_file = STRING_MULTIBYTE (file) ? ENCODE_FILE (file) : file;
 
-  encoded_dir = ENCODE_FILE (dirname);
+  encoded_dir = ENCODE_FILE (Fdirectory_file_name (dirname));
 
-  block_input ();
-  d = opendir (SSDATA (Fdirectory_file_name (encoded_dir)));
-  unblock_input ();
+  d = open_directory (SSDATA (encoded_dir), &fd);
   if (!d)
     report_file_error ("Opening directory", Fcons (dirname, Qnil));
 
   record_unwind_protect (directory_files_internal_unwind,
-                         make_save_value (d, 0));
+                         make_save_pointer (d));
 
   /* Loop reading blocks */
   /* (att3b compiler bug requires do a null comparison this way) */
@@ -480,27 +503,25 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
 
       errno = 0;
       dp = readdir (d);
-      if (dp == NULL && (0
-# ifdef EAGAIN
-                         || errno == EAGAIN
-# endif
-# ifdef EINTR
-                         || errno == EINTR
-# endif
-                         ))
-        { QUIT; continue; }
-
-      if (!dp) break;
+      if (!dp)
+        {
+          if (errno == EAGAIN || errno == EINTR)
+            {
+              QUIT;
+              continue;
+            }
+          break;
+        }
 
       len = dirent_namelen (dp);
 
       QUIT;
       if (len < SCHARS (encoded_file)
-          || 0 <= scmp (dp->d_name, SSDATA (encoded_file),
-                        SCHARS (encoded_file)))
+          || scmp (dp->d_name, SSDATA (encoded_file),
+                   SCHARS (encoded_file)) >= 0)
         continue;
 
-      if (file_name_completion_stat (encoded_dir, dp, &st) < 0)
+      if (file_name_completion_stat (fd, dp, &st) < 0)
         continue;
 
       directoryp = S_ISDIR (st.st_mode) != 0;
@@ -559,7 +580,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
                     if (skip < 0)
                       continue;
 
-                    if (0 <= scmp (dp->d_name + skip, p1, elt_len))
+                    if (scmp (dp->d_name + skip, p1, elt_len) >= 0)
                       continue;
                     break;
                   }
@@ -581,9 +602,8 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
                     skip = len - SCHARS (elt);
                     if (skip < 0) continue;
 
-                    if (0 <= scmp (dp->d_name + skip,
-                                   SSDATA (elt),
-                                   SCHARS (elt)))
+                    if (scmp (dp->d_name + skip, SSDATA (elt), SCHARS (elt))
+                        >= 0)
                       continue;
                     break;
                   }
@@ -677,10 +697,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
                                 name, zero,
                                 make_number (compare),
                                 completion_ignore_case ? Qt : Qnil);
-          ptrdiff_t matchsize
-            = (EQ (cmp, Qt)     ? compare
-               : XINT (cmp) < 0 ? - XINT (cmp) - 1
-               :                  XINT (cmp) - 1);
+          ptrdiff_t matchsize = EQ (cmp, Qt) ? compare : eabs (XINT (cmp)) - 1;
 
           if (completion_ignore_case)
             {
@@ -780,14 +797,9 @@ scmp (const char *s1, const char *s2, ptrdiff_t len)
 }
 
 static int
-file_name_completion_stat (Lisp_Object dirname, struct dirent *dp,
-                           struct stat *st_addr)
+file_name_completion_stat (int fd, struct dirent *dp, struct stat *st_addr)
 {
-  ptrdiff_t len = dirent_namelen (dp);
-  ptrdiff_t pos = SCHARS (dirname);
   int value;
-  USE_SAFE_ALLOCA;
-  char *fullname = SAFE_ALLOCA (len + pos + 2);
 
 #ifdef MSDOS
   /* Some fields of struct stat are *very* expensive to compute on MS-DOS,
@@ -800,23 +812,15 @@ file_name_completion_stat (Lisp_Object dirname, struct dirent *dp,
   _djstat_flags = _STAT_INODE | _STAT_EXEC_MAGIC | _STAT_DIRSIZE;
 #endif /* MSDOS */
 
-  memcpy (fullname, SDATA (dirname), pos);
-  if (!IS_DIRECTORY_SEP (fullname[pos - 1]))
-    fullname[pos++] = DIRECTORY_SEP;
-
-  memcpy (fullname + pos, dp->d_name, len);
-  fullname[pos + len] = 0;
-
   /* We want to return success if a link points to a nonexistent file,
      but we want to return the status for what the link points to,
      in case it is a directory.  */
-  value = lstat (fullname, st_addr);
+  value = fstatat (fd, dp->d_name, st_addr, AT_SYMLINK_NOFOLLOW);
   if (value == 0 && S_ISLNK (st_addr->st_mode))
-    stat (fullname, st_addr);
+    fstatat (fd, dp->d_name, st_addr, 0);
 #ifdef MSDOS
   _djstat_flags = save_djstat_flags;
 #endif /* MSDOS */
-  SAFE_FREE ();
   return value;
 }
 
@@ -826,7 +830,7 @@ stat_uname (struct stat *st)
 #ifdef WINDOWSNT
   return st->st_uname;
 #else
-  struct passwd *pw = (struct passwd *) getpwuid (st->st_uid);
+  struct passwd *pw = getpwuid (st->st_uid);
 
   if (pw)
     return pw->pw_name;
@@ -841,7 +845,7 @@ stat_gname (struct stat *st)
 #ifdef WINDOWSNT
   return st->st_gname;
 #else
-  struct group *gr = (struct group *) getgrgid (st->st_gid);
+  struct group *gr = getgrgid (st->st_gid);
 
   if (gr)
     return gr->gr_name;
@@ -875,7 +879,7 @@ Elements of the attribute list are:
  7. Size in bytes.
   This is a floating point number if the size is too large for an integer.
  8. File modes, as a string of ten letters or dashes as in ls -l.
- 9. t if file's gid would change if file were deleted and recreated.
+ 9. An unspecified value, present only for backward compatibility.
 10. inode number.  If it is larger than what an Emacs integer can hold,
   this is of the form (HIGH . LOW): first the high bits, then the low 16 bits.
   If even HIGH is too large for an Emacs integer, this is instead of the form
@@ -894,21 +898,8 @@ On some FAT-based filesystems, only the date of last access is recorded,
 so last access time will always be midnight of that day.  */)
   (Lisp_Object filename, Lisp_Object id_format)
 {
-  Lisp_Object values[12];
   Lisp_Object encoded;
-  struct stat s;
-#ifdef BSD4_2
-  Lisp_Object dirname;
-  struct stat sdir;
-#endif /* BSD4_2 */
-
-  /* An array to hold the mode string generated by filemodestring,
-     including its terminating space and null byte.  */
-  char modes[sizeof "-rwxr-xr-x "];
-
   Lisp_Object handler;
-  struct gcpro gcpro1;
-  char *uname = NULL, *gname = NULL;
 
   filename = Fexpand_file_name (filename, Qnil);
 
@@ -924,14 +915,41 @@ so last access time will always be midnight of that day.  */)
         return call3 (handler, Qfile_attributes, filename, id_format);
     }
 
-  GCPRO1 (filename);
   encoded = ENCODE_FILE (filename);
-  UNGCPRO;
+  return file_attributes (AT_FDCWD, SSDATA (encoded), id_format);
+}
+
+static Lisp_Object
+file_attributes (int fd, char const *name, Lisp_Object id_format)
+{
+  Lisp_Object values[12];
+  struct stat s;
+  int lstat_result;
+
+  /* An array to hold the mode string generated by filemodestring,
+     including its terminating space and null byte.  */
+  char modes[sizeof "-rwxr-xr-x "];
+
+  char *uname = NULL, *gname = NULL;
+
+#ifdef WINDOWSNT
+  /* We usually don't request accurate owner and group info, because
+     it can be very expensive on Windows to get that, and most callers
+     of 'lstat' don't need that.  But here we do want that information
+     to be accurate.  */
+  w32_stat_get_owner_group = 1;
+#endif
+
+  lstat_result = fstatat (fd, name, &s, AT_SYMLINK_NOFOLLOW);
+
+#ifdef WINDOWSNT
+  w32_stat_get_owner_group = 0;
+#endif
 
-  if (lstat (SSDATA (encoded), &s) < 0)
+  if (lstat_result < 0)
     return Qnil;
 
-  values[0] = (S_ISLNK (s.st_mode) ? Ffile_symlink_p (filename)
+  values[0] = (S_ISLNK (s.st_mode) ? emacs_readlinkat (fd, name)
                : S_ISDIR (s.st_mode) ? Qt : Qnil);
   values[1] = make_number (s.st_nlink);
 
@@ -965,17 +983,7 @@ so last access time will always be midnight of that day.  */)
 
   filemodestring (&s, modes);
   values[8] = make_string (modes, 10);
-#ifdef BSD4_2 /* file gid will be dir gid */
-  dirname = Ffile_name_directory (filename);
-  if (! NILP (dirname))
-    encoded = ENCODE_FILE (dirname);
-  if (! NILP (dirname) && stat (SDATA (encoded), &sdir) == 0)
-    values[9] = (sdir.st_gid != s.st_gid) ? Qt : Qnil;
-  else                                  /* if we can't tell, assume worst */
-    values[9] = Qt;
-#else                                   /* file gid will be egid */
-  values[9] = (s.st_gid != getegid ()) ? Qt : Qnil;
-#endif  /* not BSD4_2 */
+  values[9] = Qt;
   values[10] = INTEGER_TO_CONS (s.st_ino);
   values[11] = INTEGER_TO_CONS (s.st_dev);