From efa03dc6b9abf03bc2f8f96b484a4f4ca794a881 Mon Sep 17 00:00:00 2001
From: Joaquim <jluis@ualg.pt>
Date: Thu, 14 Nov 2024 01:37:19 +0000
Subject: [PATCH] Let the -U+t (i.e. without any argument to the +t modifier)
 plot no stamp at all.

---
 src/gmt_init.c | 29 ++++++++++++++++-------------
 src/gmt_plot.c |  9 +++++----
 2 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/gmt_init.c b/src/gmt_init.c
index fa752879bda..eb64ab08142 100644
--- a/src/gmt_init.c
+++ b/src/gmt_init.c
@@ -2527,43 +2527,46 @@ int gmt_parse_model (struct GMT_CTRL *GMT, char option, char *in_arg, unsigned i
 #define is_text(item,k)  (item[k] == 't' && item[k+1])	/* Modifier t followed by random text */
 
 /*! Parse the -U option.  Full syntax: -U[<label>][+c][+j<just>][+o<dx>[/<dy>]][+t<string>]  Old syntax was -U[[<just>]/<dx>/<dy>/][c|<label>] */
-GMT_LOCAL int gmtinit_parse_U_option (struct GMT_CTRL *GMT, char *item) {
+GMT_LOCAL int gmtinit_parse_U_option(struct GMT_CTRL *GMT, char *item) {
 	int just = 1, error = 0;
 
 	GMT->current.setting.map_logo = true;
-	gmt_M_memset (GMT->common.U.string, GMT_LEN64, char);	/* Initialize to nothing */
+	gmt_M_memset(GMT->common.U.string, GMT_LEN64, char);	/* Initialize to nothing */
 	if (!item || !item[0]) return (GMT_NOERROR);	/* Just basic -U with no args */
 
 	if (gmt_found_modifier (GMT, item, "cjot")) {	/* New syntax */
 		unsigned int pos = 0, uerr = 0;
-		int k = 1, len = (int)strlen (item);
+		int k = 1, len = (int)strlen(item);
 		char word[GMT_LEN256] = {""}, *c = NULL;
 		/* Find the first +c|j|o|t that looks like it may be a modifier and not random text */
 		while (k < len && !(is_plus(item,k) && (is_label(item,k) || is_just(item,k) || is_off(item,k) || is_text(item,k)))) k++;
-		if (k == len)	/* Modifiers were just random text */
-			strncpy (GMT->current.ps.map_logo_label, item, GMT_LEN256-1);	/* Got a label */
+		if (k == len && item[len-2] != '+' && item[len-1] != 't')	/* Modifiers were just random text (but not if it ends in "+t")*/
+			strncpy(GMT->current.ps.map_logo_label, item, GMT_LEN256-1);	/* Got a label */
 		else {	/* Appears to have gotten a valid modifier or more */
-			c = &item[k-1];	/* Start of the modifier */
+			c = (k != len) ? &item[k-1] : &item[k-2];	/* Start of the modifier. The ternary is for the ending "+t" case */
 			c[0] = '\0';	/* Chop off the + so we can parse the label, if any */
-			if (item[0]) strncpy (GMT->current.ps.map_logo_label, item, GMT_LEN256-1);	/* Got a label */
+			if (item[0]) strncpy(GMT->current.ps.map_logo_label, item, GMT_LEN256-1);	/* Got a label */
 			c[0] = '+';	/* Restore modifiers */
-			while (gmt_getmodopt (GMT, 'U', c, "cjot", &pos, word, &uerr) && uerr == 0) {
+			while (gmt_getmodopt(GMT, 'U', c, "cjot", &pos, word, &uerr) && uerr == 0) {
 				switch (word[0]) {
 					case 'c':	/* Maybe +c but only if at end of followed by another modifier */
 						if (word[1] == '+' || word[1] == '\0')	/* Use command string */
 							GMT->current.ps.logo_cmd = true;
 						break;
 					case 'j':	/* Maybe +j if the next two letters are from LCRBMT */
-						if (strchr ("LCRBMT", word[1]) && strchr ("LCRBMT", word[2]))
-							just = gmt_just_decode (GMT, &word[1], GMT->current.setting.map_logo_justify);
+						if (strchr("LCRBMT", word[1]) && strchr("LCRBMT", word[2]))
+							just = gmt_just_decode(GMT, &word[1], GMT->current.setting.map_logo_justify);
 						break;
 					case 'o':	/* Maybe +o if next letter could be part of a number */
-						if (strchr ("-+.0123456789", word[1])) {	/* Seems to be a number */
-							if ((k = gmt_get_pair (GMT, &word[1], GMT_PAIR_DIM_DUP, GMT->current.setting.map_logo_pos)) < 1) error++;
+						if (strchr("-+.0123456789", word[1])) {	/* Seems to be a number */
+							if ((k = gmt_get_pair(GMT, &word[1], GMT_PAIR_DIM_DUP, GMT->current.setting.map_logo_pos)) < 1) error++;
 						}
 						break;
 					case 't':	/* Short text to replace dateclock string */
-						strncpy (GMT->common.U.string, &word[1], GMT_LEN64);
+						if (word[1])
+							strncpy(GMT->common.U.string, &word[1], GMT_LEN64);
+						else
+							GMT->common.U.string[0] = ' ';
 						break;
 					default: break;	/* These are caught in gmt_getmodopt so break is just for Coverity */
 				}
diff --git a/src/gmt_plot.c b/src/gmt_plot.c
index b94f7db1e79..9f23127b00f 100644
--- a/src/gmt_plot.c
+++ b/src/gmt_plot.c
@@ -3181,7 +3181,7 @@ GMT_LOCAL void gmtplot_cube_box (struct GMT_CTRL *GMT, struct PSL_CTRL *PSL, int
 	PSL_plotline (PSL, xx, yy, 4, PSL_MOVE|PSL_STROKE);
 }
 
-GMT_LOCAL void gmtplot_timestamp (struct GMT_CTRL *GMT, struct PSL_CTRL *PSL, double x, double y, unsigned int justify, char *U_label) {
+GMT_LOCAL void gmtplot_timestamp(struct GMT_CTRL *GMT, struct PSL_CTRL *PSL, double x, double y, unsigned int justify, char *U_label) {
 	/* x, y = location of the time stamp box
 	 * justify indicates the corner of the box that (x,y) refers to, see below
 	 * U_label = label to be plotted to the right of the box
@@ -3199,9 +3199,10 @@ GMT_LOCAL void gmtplot_timestamp (struct GMT_CTRL *GMT, struct PSL_CTRL *PSL, do
 
 	/* Plot time string in format defined by format_time_stamp */
 
-	if (GMT->common.U.string[0])	/* Override UNIX time stamp with custom short string */
-		snprintf (label, GMT_LEN256, "  %s  ", GMT->common.U.string);
-	else {	/* Build UNIX time stamp based on current time */
+	if (GMT->common.U.string[0]) {	/* Override time stamp with custom short string. But write nothing if only one char and == ' ' */
+		if (GMT->common.U.string[0] != ' ' || GMT->common.U.string[1]) snprintf(label, GMT_LEN256, "  %s  ", GMT->common.U.string);
+	}
+	else {	/* Build time stamp based on current time */
 		time_t right_now = time ((time_t *)0);
 		char text[GMT_LEN256] = {""};
 		strftime (text, sizeof(text), GMT->current.setting.format_time_stamp, localtime (&right_now));