Do only one call to GetVersionEx in the common case.

[pspp] / lib / fchdir.c

diff --git a/lib/fchdir.c b/lib/fchdir.c
index 9b64e0294bcd823a4b5149d35d868cb4d9dfd69a..19f02c34c5982c4fa57caf7f32ab5244b13301b2 100644 (file)
--- a/lib/fchdir.c
+++ b/lib/fchdir.c
@@ -29,12 +29,19 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
-#include "canonicalize.h"
-
 #ifndef REPLACE_OPEN_DIRECTORY
 # define REPLACE_OPEN_DIRECTORY 0
 #endif
 
+#ifndef HAVE_CANONICALIZE_FILE_NAME
+# if GNULIB_CANONICALIZE || GNULIB_CANONICALIZE_LGPL
+#  define HAVE_CANONICALIZE_FILE_NAME 1
+# else
+#  define HAVE_CANONICALIZE_FILE_NAME 0
+#  define canonicalize_file_name(name) NULL
+# endif
+#endif
+
 /* This replacement assumes that a directory is not renamed while opened
    through a file descriptor.
 
@@ -65,11 +72,11 @@ ensure_dirs_slot (size_t fd)
 
       new_allocated = 2 * dirs_allocated + 1;
       if (new_allocated <= fd)
-       new_allocated = fd + 1;
+        new_allocated = fd + 1;
       new_dirs =
-       (dirs != NULL
-        ? (dir_info_t *) realloc (dirs, new_allocated * sizeof *dirs)
-        : (dir_info_t *) malloc (new_allocated * sizeof *dirs));
+        (dirs != NULL
+         ? (dir_info_t *) realloc (dirs, new_allocated * sizeof *dirs)
+         : (dir_info_t *) malloc (new_allocated * sizeof *dirs));
       if (new_dirs == NULL)
         return false;
       memset (new_dirs + dirs_allocated, 0,
@@ -80,6 +87,39 @@ ensure_dirs_slot (size_t fd)
   return true;
 }
 
+/* Return the canonical name of DIR in malloc'd storage.  */
+static char *
+get_name (char const *dir)
+{
+  char *result;
+  if (REPLACE_OPEN_DIRECTORY || !HAVE_CANONICALIZE_FILE_NAME)
+    {
+      /* The function canonicalize_file_name has not yet been ported
+         to mingw, with all its drive letter and backslash quirks.
+         Fortunately, getcwd is reliable in this case, but we ensure
+         we can get back to where we started before using it.  Treat
+         "." as a special case, as it is frequently encountered.  */
+      char *cwd = getcwd (NULL, 0);
+      int saved_errno;
+      if (dir[0] == '.' && dir[1] == '\0')
+        return cwd;
+      if (chdir (cwd))
+        return NULL;
+      result = chdir (dir) ? NULL : getcwd (NULL, 0);
+      saved_errno = errno;
+      if (chdir (cwd))
+        abort ();
+      free (cwd);
+      errno = saved_errno;
+    }
+  else
+    {
+      /* Avoid changing the directory.  */
+      result = canonicalize_file_name (dir);
+    }
+  return result;
+}
+
 /* Hook into the gnulib replacements for open() and close() to keep track
    of the open file descriptors.  */
 
@@ -110,7 +150,7 @@ _gl_register_fd (int fd, const char *filename)
       || (fstat (fd, &statbuf) == 0 && S_ISDIR (statbuf.st_mode)))
     {
       if (!ensure_dirs_slot (fd)
-          || (dirs[fd].name = canonicalize_file_name (filename)) == NULL)
+          || (dirs[fd].name = get_name (filename)) == NULL)
         {
           int saved_errno = errno;
           close (fd);
@@ -154,6 +194,25 @@ _gl_register_dup (int oldfd, int newfd)
   return newfd;
 }
 
+/* If FD is currently visiting a directory, then return the name of
+   that directory.  Otherwise, return NULL and set errno.  */
+const char *
+_gl_directory_name (int fd)
+{
+  if (0 <= fd && fd < dirs_allocated && dirs[fd].name != NULL)
+    return dirs[fd].name;
+  /* At this point, fd is either invalid, or open but not a directory.
+     If dup2 fails, errno is correctly EBADF.  */
+  if (0 <= fd)
+    {
+      if (dup2 (fd, fd) == fd)
+        errno = ENOTDIR;
+    }
+  else
+    errno = EBADF;
+  return NULL;
+}
+
 /* Return stat information about FD in STATBUF.  Needed when
    rpl_open() used a dummy file to work around an open() that can't
    normally visit directories.  */
@@ -222,16 +281,6 @@ rpl_dup (int oldfd)
 int
 fchdir (int fd)
 {
-  if (fd >= 0 && fd < dirs_allocated && dirs[fd].name != NULL)
-    return chdir (dirs[fd].name);
-  /* At this point, fd is either invalid, or open but not a directory.
-     If dup2 fails, errno is correctly EBADF.  */
-  if (0 <= fd)
-    {
-      if (dup2 (fd, fd) == fd)
-        errno = ENOTDIR;
-    }
-  else
-    errno = EBADF;
-  return -1;
+  const char *name = _gl_directory_name (fd);
+  return name ? chdir (name) : -1;
 }