Fix auto-legend using wrong symbol for -Sf fault decorations (#9066)

src/gmt_init.c

@@ -20455,6 +20455,14 @@ void gmt_add_legend_item (struct GMTAPI_CTRL *API, struct GMT_SYMBOL *S, bool do
 		else if (symbol == GMT_SYMBOL_CUSTOM) { /* Custom symbol */
 			fprintf (fp, "S - %c%s %s %s %s - %s\n", GMT_SYMBOL_CUSTOM, S->custom->name, size_string, (do_fill) ? gmtlib_putfill (API->GMT, fill) : "-", (do_line) ? gmt_putpen (API->GMT, pen) : "-", label);
 		}
+		else if (symbol == GMT_SYMBOL_FRONT) {	/* Front symbol: must pass along the front-type and sense modifiers or pslegend will default to +l+b (left box) for all entries */
+			char scode[GMT_LEN64] = {""};
+			static char f_type[7] = {'f', 'v', 't', 's', 'S', 'c', 'b'};	/* Maps GMT_FRONT_* enum to its -Sf modifier letter */
+			sprintf (scode, "f+%c", f_type[S->f.f_symbol]);
+			if (S->f.f_sense == GMT_FRONT_LEFT) strcat (scode, "+l");
+			else if (S->f.f_sense == GMT_FRONT_RIGHT) strcat (scode, "+r");
+			fprintf (fp, "S - %s %s %s %s - %s\n", scode, size_string, (do_fill) ? gmtlib_putfill (API->GMT, fill) : "-", (do_line) ? gmt_putpen (API->GMT, pen) : "-", label);
+		}		
 		else
 			fprintf (fp, "S - %c %s %s %s - %s\n", symbol, size_string, (do_fill) ? gmtlib_putfill (API->GMT, fill) : "-", (do_line) ? gmt_putpen (API->GMT, pen) : "-", label);
 	}

src/pslegend.c

@@ -1602,7 +1602,7 @@ EXTERN_MSC int GMT_pslegend (void *V_API, int mode, void *args) {
 								/* Place pen and fill colors in segment header */
 								sprintf (buffer, "-Sf%s/%gi%s", B, tlen, sub);
 								if (txt_c[0] != '-') {strcat (buffer, " -G"); strcat (buffer, txt_c);}
-								if (txt_d[0] != '-') {strcat (buffer, " -W"); strcat (buffer, txt_d);}
+								strcat (buffer, " -W"); strcat (buffer, (txt_d[0] != '-') ? txt_d : gmt_putpen (GMT, &GMT->current.setting.map_default_pen));	/* Always give an explicit pen (given or default) so this segment does not inherit the previous entry's pen */
 								/* Prepare next output segment */
 								if ((D[FRONT] = pslegend_get_dataset_pointer (API, D[FRONT], GMT_IS_LINE, GMT_SMALL_CHUNK, 2U, 2U, false)) == NULL) return (API->error);
 								S[FRONT] = pslegend_get_segment (D, FRONT, n_fronts);	/* Next front segment */
@@ -1623,7 +1623,7 @@ EXTERN_MSC int GMT_pslegend (void *V_API, int mode, void *args) {
 								x = 0.5 * length;
 								/* Place pen and fill colors in segment header */
 								sprintf (buffer, "-S%s", symbol);
-								if (txt_d[0] != '-') {strcat (buffer, " -W"); strcat (buffer, txt_d);}
+								strcat (buffer, " -W"); strcat (buffer, (txt_d[0] != '-') ? txt_d : gmt_putpen (GMT, &GMT->current.setting.map_default_pen));	/* Always give an explicit pen (given or default) so this segment does not inherit the previous entry's pen */
 								S[QLINE] = pslegend_get_segment (D, QLINE, n_quoted_lines);	/* Next quoted line segment */
 								S[QLINE]->header = strdup (buffer);
 								GMT_Report (API, GMT_MSG_DEBUG, "QLINE: %s\n", buffer);
@@ -1642,7 +1642,7 @@ EXTERN_MSC int GMT_pslegend (void *V_API, int mode, void *args) {
 								x = 0.5 * length;
 								/* Place pen and fill colors in segment header */
 								sprintf (buffer, "-S%s", symbol);
-								if (txt_d[0] != '-') {strcat (buffer, " -W"); strcat (buffer, txt_d);}
+								strcat (buffer, " -W"); strcat (buffer, (txt_d[0] != '-') ? txt_d : gmt_putpen (GMT, &GMT->current.setting.map_default_pen));	/* Always give an explicit pen (given or default) so this segment does not inherit the previous entry's pen */
 								S[DLINE] = pslegend_get_segment (D, DLINE, n_decorated_lines);	/* Next decorated line segment */
 								S[DLINE]->header = strdup (buffer);
 								GMT_Report (API, GMT_MSG_DEBUG, "DLINE: %s\n", buffer);

test/pslegend/autolegendfront.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+#
+# Test auto-legend for front (fault) symbols (-Sf).
+#
+# GRAPHICSMAGICK_RMS = 0.02
+# GMT_KNOWN_FAILURE
+#
+# Regression test for issue #9066:
+#  1) Each auto-legend entry must show the correct front sub-type
+#     (e.g., +c circle vs +b box), not always a box.
+#  2) An entry with no explicit -W must not inherit the pen from a
+#     previous entry that did specify one (here, "circle thick" uses
+#     an explicit thick red pen, while "box" specifies no pen at all
+#     and must fall back to the default pen, not thick red).
+cat << EOF > t1.txt
+0 1
+1 1
+EOF
+cat << EOF > t2.txt
+0 2
+1 2
+EOF
+gmt begin autolegendfront ps
+	gmt basemap -R0/1/0/5 -JX5c -Bf
+	gmt plot -Wthick,red -Gblack  -Sf2+c+r t2.txt -l"circle thick"
+	gmt plot             -Gpurple -Sf2+b+r t1.txt -l"box"
+gmt end
+
+rm t*.txt