Avoid grave accent quoting in stderr diagnostics

A few Emacs diagnostics go directly to stderr, and so can't easily
contain curved quotes (as non-UTF-8 locales might mishandle them).
Instead of bothering to add support for this rarity, reword the
diagnostics so that they don't use grave accent to quote.
* src/alloc.c (mark_memory): Fix comment.
* src/buffer.c (init_buffer):
* src/dispnew.c (init_display):
* src/emacs.c (main, sort_args):
* src/lread.c (dir_warning):
* src/term.c (init_tty):
* src/unexmacosx.c (unexec):
* src/xfns.c (select_visual):
* src/xterm.c (cvt_string_to_pixel, x_io_error_quitter):
Reword stderr diagnostics to avoid quoting `like this'.
* src/unexmacosx.c: Include errno.h.
* src/xfns.c (select_visual): Encode value for locale.

src/alloc.c

@@ -4775,7 +4775,7 @@ mark_memory (void *start, void *end)
        Lisp_Object obj = build_string ("test");
        struct Lisp_String *s = XSTRING (obj);
        Fgarbage_collect ();
-       fprintf (stderr, "test `%s'\n", s->data);
+       fprintf (stderr, "test '%s'\n", s->data);
        return Qnil;
      }
 

src/buffer.c

@@ -5285,7 +5285,7 @@ init_buffer (int initialized)
   pwd = get_current_dir_name ();
 
   if (!pwd)
-    fatal ("`get_current_dir_name' failed: %s\n", strerror (errno));
+    fatal ("get_current_dir_name: %s\n", strerror (errno));
 
   /* Maybe this should really use some standard subroutine
      whose definition is filename syntax dependent.  */
@@ -5295,7 +5295,7 @@ init_buffer (int initialized)
       /* Grow buffer to add directory separator and '\0'.  */
       pwd = realloc (pwd, len + 2);
       if (!pwd)
-	fatal ("`get_current_dir_name' failed: %s\n", strerror (errno));
+	fatal ("get_current_dir_name: %s\n", strerror (errno));
       pwd[len] = DIRECTORY_SEP;
       pwd[len + 1] = '\0';
       len++;

src/dispnew.c

@@ -6036,10 +6036,10 @@ init_display (void)
     {
 #ifdef HAVE_WINDOW_SYSTEM
       if (! inhibit_window_system)
-	fprintf (stderr, "Please set the environment variable DISPLAY or TERM (see `tset').\n");
+	fprintf (stderr, "Please set the environment variable DISPLAY or TERM (see 'tset').\n");
       else
 #endif /* HAVE_WINDOW_SYSTEM */
-	fprintf (stderr, "Please set the environment variable TERM; see `tset'.\n");
+	fprintf (stderr, "Please set the environment variable TERM; see 'tset'.\n");
       exit (1);
     }
 

src/emacs.c

@@ -776,12 +776,12 @@ main (int argc, char **argv)
 	  tem2 = Fsymbol_value (intern_c_string ("emacs-copyright"));
 	  if (!STRINGP (tem))
 	    {
-	      fprintf (stderr, "Invalid value of `emacs-version'\n");
+	      fprintf (stderr, "Invalid value of 'emacs-version'\n");
 	      exit (1);
 	    }
 	  if (!STRINGP (tem2))
 	    {
-	      fprintf (stderr, "Invalid value of `emacs-copyright'\n");
+	      fprintf (stderr, "Invalid value of 'emacs-copyright'\n");
 	      exit (1);
 	    }
 	  else
@@ -1796,7 +1796,7 @@ sort_args (int argc, char **argv)
 		options[from] = standard_args[i].nargs;
 		priority[from] = standard_args[i].priority;
 		if (from + standard_args[i].nargs >= argc)
-		  fatal ("Option `%s' requires an argument\n", argv[from]);
+		  fatal ("Option '%s' requires an argument\n", argv[from]);
 		from += standard_args[i].nargs;
 		goto done;
 	      }
@@ -1833,7 +1833,7 @@ sort_args (int argc, char **argv)
 		  if (equals != 0)
 		    options[from] = 0;
 		  if (from + options[from] >= argc)
-		    fatal ("Option `%s' requires an argument\n", argv[from]);
+		    fatal ("Option '%s' requires an argument\n", argv[from]);
 		  from += options[from];
 		}
 	      /* FIXME When match < 0, shouldn't there be some error,

src/lread.c

@@ -4418,9 +4418,10 @@ init_lread (void)
 void
 dir_warning (char const *use, Lisp_Object dirname)
 {
-  static char const format[] = "Warning: %s `%s': %s\n";
+  static char const format[] = "Warning: %s '%s': %s\n";
   int access_errno = errno;
-  fprintf (stderr, format, use, SSDATA (dirname), strerror (access_errno));
+  fprintf (stderr, format, use, SSDATA (ENCODE_SYSTEM (dirname)),
+	   strerror (access_errno));
 
   /* Don't log the warning before we've initialized!!  */
   if (initialized)

src/term.c

@@ -4028,12 +4028,12 @@ init_tty (const char *name, const char *terminal_type, bool must_succeed)
                    "Terminal type %s is not defined",
                    "Terminal type %s is not defined.\n\
 If that is not the actual type of terminal you have,\n\
-use the Bourne shell command `TERM=... export TERM' (C-shell:\n\
-`setenv TERM ...') to specify the correct type.  It may be necessary\n"
+use the Bourne shell command 'TERM=...; export TERM' (C-shell:\n\
+'setenv TERM ...') to specify the correct type.  It may be necessary\n"
 #ifdef TERMINFO
-"to do `unset TERMINFO' (C-shell: `unsetenv TERMINFO') as well.",
+"to do 'unset TERMINFO' (C-shell: 'unsetenv TERMINFO') as well.",
 #else
-"to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
+"to do 'unset TERMCAP' (C-shell: 'unsetenv TERMCAP') as well.",
 #endif
                    terminal_type);
     }
@@ -4307,12 +4307,12 @@ use the Bourne shell command `TERM=... export TERM' (C-shell:\n\
                    "Terminal type \"%s\" is not powerful enough to run Emacs.\n\
 It lacks the ability to position the cursor.\n\
 If that is not the actual type of terminal you have,\n\
-use the Bourne shell command `TERM=... export TERM' (C-shell:\n\
-`setenv TERM ...') to specify the correct type.  It may be necessary\n"
+use the Bourne shell command 'TERM=...; export TERM' (C-shell:\n\
+'setenv TERM ...') to specify the correct type.  It may be necessary\n"
 # ifdef TERMINFO
-"to do `unset TERMINFO' (C-shell: `unsetenv TERMINFO') as well.",
+"to do 'unset TERMINFO' (C-shell: 'unsetenv TERMINFO') as well.",
 # else /* TERMCAP */
-"to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
+"to do 'unset TERMCAP' (C-shell: 'unsetenv TERMCAP') as well.",
 # endif /* TERMINFO */
                    terminal_type);
     }

src/unexmacosx.c

@@ -99,6 +99,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "unexec.h"
 #include "lisp.h"
 
+#include <errno.h>
 #include <stdio.h>
 #include <fcntl.h>
 #include <stdarg.h>
@@ -1264,14 +1265,14 @@ unexec (const char *outfile, const char *infile)
   infd = emacs_open (infile, O_RDONLY, 0);
   if (infd < 0)
     {
-      unexec_error ("cannot open input file `%s'", infile);
+      unexec_error ("%s: %s", infile, strerror (errno));
     }
 
   outfd = emacs_open (outfile, O_WRONLY | O_TRUNC | O_CREAT, 0777);
   if (outfd < 0)
     {
       emacs_close (infd);
-      unexec_error ("cannot open output file `%s'", outfile);
+      unexec_error ("%s: %s", outfile, strerror (errno));
     }
 
   build_region_list ();

src/xfns.c

@@ -4519,7 +4519,8 @@ select_visual (struct x_display_info *dpyinfo)
       if (class == -1
 	  || !XMatchVisualInfo (dpy, XScreenNumberOfScreen (screen),
 				dpyinfo->n_planes, class, &vinfo))
-	fatal ("Invalid visual specification `%s'", SDATA (value));
+	fatal ("Invalid visual specification '%s'",
+	       SSDATA (ENCODE_SYSTEM (value)));
 
       dpyinfo->visual = vinfo.visual;
     }

src/xterm.c

@@ -2091,7 +2091,7 @@ cvt_string_to_pixel (Display *dpy, XrmValue *args, Cardinal *nargs,
       params[0] = color_name;
       XtAppWarningMsg (XtDisplayToApplicationContext (dpy),
 		       "badValue", "cvt_string_to_pixel",
-		       "XtToolkitError", "Invalid color `%s'",
+		       "XtToolkitError", "Invalid color '%s'",
 		       params, &nparams);
       return False;
     }
@@ -9388,7 +9388,7 @@ x_io_error_quitter (Display *display)
 {
   char buf[256];
 
-  snprintf (buf, sizeof buf, "Connection lost to X server `%s'",
+  snprintf (buf, sizeof buf, "Connection lost to X server '%s'",
 	    DisplayString (display));
   x_connection_closed (display, buf, true);
   return 0;