+/*
+ * Exiting a video mode should not duplicate sgr0
+ */
+static void
+check_exit_attribute(const char *name, char *test, char *trimmed, char *untrimmed)
+{
+ if (VALID_STRING(test) && (trimmed != 0)) {
+ if (similar_sgr(-1, trimmed, test) ||
+ similar_sgr(-1, untrimmed, test)) {
+ _nc_warning("%s matches exit_attribute_mode", name);
+ }
+ }
+}
+
+/*
+ * Returns true if the string looks like a standard SGR string.
+ */
+static bool
+is_sgr_string(char *value)
+{
+ bool result = FALSE;
+
+ if (VALID_STRING(value)) {
+ if (value[0] == '\033' && value[1] == '[') {
+ result = TRUE;
+ value += 2;
+ } else if (UChar(value[0]) == 0x9a) {
+ result = TRUE;
+ value += 1;
+ }
+ if (result) {
+ int ch;
+ while ((ch = UChar(*value++)) != '\0') {
+ if (isdigit(ch) || ch == ';') {
+ ;
+ } else if (ch == 'm' && *value == '\0') {
+ ;
+ } else {
+ result = FALSE;
+ break;
+ }
+ }
+ }
+ }
+ return result;
+}
+
+/*
+ * Check if the given capability contains a given SGR attribute.
+ */
+static void
+check_sgr_param(TERMTYPE *tp, int code, const char *name, char *value)
+{
+ if (VALID_STRING(value)) {
+ int ncv = ((code != 0) ? (1 << (code - 1)) : 0);
+ char *test = tgoto(value, 0, 0);
+ if (is_sgr_string(test)) {
+ int param = 0;
+ int count = 0;
+ int skips = 0;
+ int color = (value == set_a_foreground ||
+ value == set_a_background ||
+ value == set_foreground ||
+ value == set_background);
+ while (*test != 0) {
+ if (isdigit(UChar(*test))) {
+ param = 10 * param + (*test - '0');
+ ++count;
+ } else {
+ if (count) {
+ /*
+ * Avoid unnecessary warning for xterm 256color codes.
+ */
+ if (color && (param == 38 || param == 48))
+ skips = 3;
+ if ((skips-- <= 0) && (param == code))
+ break;
+ }
+ count = 0;
+ param = 0;
+ }
+ ++test;
+ }
+ if (count != 0 && param == code) {
+ if (code == 0 ||
+ no_color_video < 0 ||
+ !(no_color_video & ncv)) {
+ _nc_warning("\"%s\" SGR-attribute used in %s",
+ sgr_names[code],
+ name);
+ }
+ }
+ }
+ }
+}
+