add connections guard

Co-authored-by: aitap <[email protected]>

Author: ben-schwen

src/freadR.c

@@ -742,6 +742,9 @@ void progress(int p, int eta)
 
 // Spill connection contents to a tempfile so R-level fread can treat it like a filename
 SEXP spillConnectionToFile(SEXP connection, SEXP tempfile_path, SEXP nrows_limit) {
+#if R_CONNECTIONS_VERSION != 1
+INTERNAL_STOP(_("spillConnectionToFile: unexpected R_CONNECTIONS_VERSION = %d", R_CONNECTIONS_VERSION)); // # nocov
+#else
   if (!isString(tempfile_path) || LENGTH(tempfile_path) != 1) {
     INTERNAL_STOP(_("spillConnectionToFile: tempfile_path must be a single string")); // # nocov
   }
@@ -814,6 +817,7 @@ SEXP spillConnectionToFile(SEXP connection, SEXP tempfile_path, SEXP nrows_limit
   free(buffer);
   fclose(outfile);
   return ScalarReal((double)total_read);
+#endif // was R_CONNECTIONS_VERSION not != 1?
 }
 
 void halt__(bool warn, const char *format, ...)