[tin 1.7.x] online help fix

below is a fix for
| o  the decription in the online 'h'elp for is dublicated (in
|    all levels) if the "same" key is mapped to the same function twice
|    (e.g: GroupReadBasenote      ^J      ^M)
|    | Group/thread/article operations
|    | -------------------------------
|    | <CR>      read chosen group
|    | <CR>      read chosen group

--- help.c.o	2005-04-19 16:00:08.000000000 +0200
+++ help.c	2005-04-19 16:03:06.000000000 +0200
@@ -443,19 +443,21 @@
 	const t_help_page *helppage,
 	const struct keylist keys)
 {
-	char *buf;
+	char *buf = my_malloc(LEN);
+	char *last = my_malloc(LEN);
 	char key[MAXKEYLEN];
 	/*
 	 * length is only needed to pass it to expand_ctrl_chars()
 	 * we have no need for the value
 	 */
 	int length;
-
-	buf = my_malloc(LEN);
+	size_t i;
 
 	if (!helppage)
 		return;
 
+	last[0] = '\0';
+
 	while (helppage->helptext) {
 		if (helppage->func == NOT_ASSIGNED) {
 			/*
@@ -464,23 +466,24 @@
 			 */
 			buf = my_realloc(buf, LEN);
 
-			if (!strlen(helppage->helptext))	/* avoid empty string translations */
-				snprintf(buf, LEN, "%s", helppage->helptext);
+			if (!strlen(helppage->helptext))	/* avoid translation of empty strings */
+				snprintf(buf, LEN, "\n");
 			else
 				snprintf(buf, LEN, "%s", _(helppage->helptext));
 			buf[LEN - 1] = '\0';
 			expand_ctrl_chars(&buf, &length, 8);
 			fprintf(fp, "%s", buf);
 		} else {
-			size_t i;
-
 			for (i = 0; i < keys.used; i++) {
 				if (keys.list[i].function == helppage->func) {
 					buf = my_realloc(buf, LEN);
 					snprintf(buf, LEN, "%s\t  %s", printascii(key, keys.list[i].key), _(helppage->helptext));
 					buf[LEN - 1] = '\0';
 					expand_ctrl_chars(&buf, &length, 8);
-					fprintf(fp, "%s", buf);
+					if (strcmp(last, buf)) {
+						fprintf(fp, "%s", buf);
+						strncpy(last, buf, LEN);
+					}
 				}
 			}
 		}
@@ -488,6 +491,7 @@
 	}
 
 	free(buf);
+	free(last);
 }