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/tac.c b/src/tac.c
index 57e7e761d..1029de63b 100644
--- a/src/tac.c
+++ b/src/tac.c
@@ -660,7 +660,7 @@ main (int argc, char **argv)
       error_message = re_compile_pattern (separator, strlen (separator),
                                           &compiled_separator);
       if (error_message)
-        error (EXIT_FAILURE, 0, "%s", error_message);
+        error (EXIT_FAILURE, 0, "%s", (error_message));
     }
   else
     match_length = sentinel_length = strlen (separator);