all: quote string arguments in error messages

These strings are often file names or other user specified
parameters, which can give confusing errors in
the presence of unexpected characters for example.

* cfg.mk (sc_error_quotes): A new syntax check rule.
* src/*.c: Wrap error() string arguments with quote().
* tests/: Adjust accordingly.
* NEWS: Mention the improvement.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/who.c b/src/who.c
index 0a09411f4..2260bc1e9 100644
--- a/src/who.c
+++ b/src/who.c
@@ -620,7 +620,7 @@ who (const char *filename, int options)
   STRUCT_UTMP *utmp_buf;
 
   if (read_utmp (filename, &n_users, &utmp_buf, options) != 0)
-    error (EXIT_FAILURE, errno, "%s", filename);
+    error (EXIT_FAILURE, errno, "%s", quote (filename));
 
   if (short_list)
     list_entries_who (n_users, utmp_buf);