Fix file name encodings in diagnostics

Also, close some minor races when opening image files, by opening
them once instead of multiple times.
* src/gtkutil.c (xg_get_image_for_pixmap):
* src/image.c (xpm_load, tiff_load, gif_load, imagemagick_load)
(svg_load):
* src/nsimage.m (allocInitFromFile:):
* src/xfns.c (xg_set_icon):
Encode file name, since x_find_image_file no longer does that.
* src/image.c (x_find_image_fd): New function.
(x_find_image_file): Use it.  Do not encode resulting file name,
since callers sometimes need it decoded.
(slurp_file): File arg is now a fd, not a file name.
All callers changed.  This saves us having to open the file twice.
(xbm_load, xpm_load, pbm_load, png_load_body, jpeg_load_body)
(svg_load):
Use x_find_image_fd and fdopen to save a file-open.
Report file name that failed.
* src/lread.c (openp): If PREDICATE is t, open the file in binary mode.

1 files changed, 8 insertions, 5 deletions

diff --git a/src/lread.c b/src/lread.c
index ebd594c1a16..77a62118a39 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -1403,7 +1403,8 @@ directories, make sure the PREDICATE function returns `dir-ok' for them.  */)
    SUFFIXES is a list of strings containing possible suffixes.
    The empty suffix is automatically added if the list is empty.
 
-   PREDICATE non-nil means don't open the files,
+   PREDICATE t means the files are binary.
+   PREDICATE non-nil and non-t means don't open the files,
    just look for one that satisfies the predicate.  In this case,
    return 1 on success.  The predicate can be a lisp function or
    an integer to pass to `access' (in which case file-name-handlers
@@ -1418,7 +1419,7 @@ directories, make sure the PREDICATE function returns `dir-ok' for them.  */)
 
    If NEWER is true, try all SUFFIXes and return the result for the
    newest file that exists.  Does not apply to remote files,
-   or if PREDICATE is specified.  */
+   or if a non-nil and non-t PREDICATE is specified.  */
 
 int
 openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes,
@@ -1520,10 +1521,11 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes,
           else
             string = make_string (fn, fnlen);
           handler = Ffind_file_name_handler (string, Qfile_exists_p);
-          if ((!NILP (handler) || !NILP (predicate)) && !NATNUMP (predicate))
+          if ((!NILP (handler) || (!NILP (predicate) && !EQ (predicate, Qt)))
+              && !NATNUMP (predicate))
             {
               bool exists;
-              if (NILP (predicate))
+              if (NILP (predicate) || EQ (predicate, Qt))
                 exists = !NILP (Ffile_readable_p (string));
               else
                 {
@@ -1577,7 +1579,8 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes,
                 }
               else
                 {
-                  fd = emacs_open (pfn, O_RDONLY, 0);
+                  int oflags = O_RDONLY + (NILP (predicate) ? 0 : O_BINARY);
+                  fd = emacs_open (pfn, oflags, 0);
                   if (fd < 0)
                     {
                       if (errno != ENOENT)