Use new q ‘format’ flag when fixing quotes in C

* src/image.c (image_size_error): New function.  All uses of
image_error with "Invalid image size ..."  changed to use it.
* src/image.c (image_size_error, xbm_load_image, xbm_load)
(xpm_load, xpm_load_image, xpm_load, pbm_load, png_load_body)
(jpeg_load_body, tiff_load, gif_load, imagemagick_load_image)
(imagemagick_load, svg_load, svg_load_image, gs_load)
(x_kill_gs_process):
* src/lread.c (load_warn_old_style_backquotes):
* src/xfaces.c (load_pixmap):
* src/xselect.c (x_clipboard_manager_error_1):
Use %qs, not uLSQM and uRSQM.
* src/syntax.c (Finternal_describe_syntax_value):
Prefer Fsubstitute_command_keys to Fformat, as this lets
us use AUTO_STRING.
* src/xdisp.c (vadd_to_log): Use AUTO_STRING on the format argument,
as it's now guaranteed to be ASCII.
* src/xselect.c (x_clipboard_manager_error_2):
Avoid grave accent in low-level stderr diagnostic.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/syntax.c b/src/syntax.c
index d543a5f9823..30560affdf0 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -1333,10 +1333,11 @@ DEFUN ("internal-describe-syntax-value", Finternal_describe_syntax_value,
     insert_string (" (nestable)");
 
   if (prefix)
-    insert1 (CALLN (Fformat,
-                    (build_string
-                     (",\n\t  is a prefix character for "
-                      uLSQM"backward-prefix-chars"uRSQM))));
+    {
+      AUTO_STRING (prefixdoc,
+                   ",\n\t  is a prefix character for `backward-prefix-chars'");
+      insert1 (Fsubstitute_command_keys (prefixdoc));
+    }
 
   return syntax;
 }