viewer, editor: Various robustness and UX improvements.

* viewer.c: Fix was_unicode calculation to avoid spurious aborts.
* Reduce FETCHLIST interval, since even an interval of 180
  can take up to 15 seconds to load a folder.
* SMTP: Don't send addresses with double <<>> for RCPT.
* editor: Add spaces at beginning of quoted lines, as with viewer, for
  readability.
* editor: Fix erroneous extra spaces at end of format=flowed lines,
  caused by duplicate logic that would add a space in this case.
* editor: Distinguish between message not sent and sent but not saved.
* imap: Avoid infinite loop by breaking early if flushed input is empty.
* IMAP APPEND: Fix memory leak of flags.

editor.c

@@ -623,6 +623,8 @@ static int send_message(struct client *client, FIELD *fields[NUM_FIELDS + 1], st
 					increment_stats_by_size(client->sent_mbox, msglen, 0);
 					increment_stats_by_size(&client->mailboxes[0], msglen, 0); /* Aggregate stats */
 				}
+			} else {
+				res = 2;
 			}
 		}
 	}
@@ -811,6 +813,13 @@ static void format_and_quote_body(FORM *form, const char *body, int addquotes)
 #endif
 		if (!strncmp(s, "\r\n", 2)) {
 			if (outputcol > 0 && s[-1] == ' ' && *(s + 2) && next_n_quotes(s + 2, quote_depth)) {
+				/* We just printed the format=flowed space at the end of the input line,
+				 * but that conflicts with this path:
+				 * if (addquotes && inputcol == 0 && quote_depth == 0) {
+				 */
+				form_driver(form, REQ_DEL_PREV);
+				outputcol--;
+
 				client_debug(9, "format=flowed line break on row %d, col %d", row, outputcol);
 				/* This is a format=flowed soft line wrap, don't actually wrap */
 				s += STRLEN("\r\n"); /* Skip CR LF */
@@ -820,6 +829,9 @@ static void format_and_quote_body(FORM *form, const char *body, int addquotes)
 					/* Skip space, since we already printed the format=flowed space at end of previous line */
 					inputcol++;
 					s++;
+					client_debug(9, "Skipped format=flowed space, next character is '%c'", *s);
+				} else {
+					client_debug(9, "Didn't skip format=flowed space, next character is '%c'", *s);
 				}
 				/* Resume */
 			} else {
@@ -853,14 +865,18 @@ static void format_and_quote_body(FORM *form, const char *body, int addquotes)
 				last_sp = memrchr(s - outputcol, ' ', outputcol);
 				if (last_sp) {
 					int diff = s - 1 - last_sp;
-					client_debug(9, "Backing up %d characters", diff);
-					for (j = 0; j < diff; j++) {
-						form_driver(form, REQ_DEL_PREV);
+					if (diff < outputcol - 2) {
+						client_debug(9, "Backing up %d characters", diff);
+						for (j = 0; j < diff; j++) {
+							form_driver(form, REQ_DEL_PREV);
+						}
+						/* Back up and break the line there instead */
+						s -= diff;
+						outputcol -= diff;
+						inputcol -= diff;
+					} else {
+						client_debug(1, "Can't wrap this line: %d/%d", diff, outputcol);
 					}
-					/* Back up and break the line there instead */
-					s -= diff;
-					outputcol -= diff;
-					inputcol -= diff;
 				}
 				outputcol = 0;
 				form_driver(form, REQ_NEW_LINE);
@@ -871,7 +887,7 @@ static void format_and_quote_body(FORM *form, const char *body, int addquotes)
 				for (j = 0; j < quote_depth; j++) {
 					FORM_PUTC('>');
 				}
-				if (quote_depth) { /* Condition added since down below we also add a space, but only if quote_depth is 0 */
+				if (quote_depth || *s != ' ') { /* Condition added since down below we also add a space, but only if quote_depth is 0 */
 					/* Ensure there's a space after the quotes before continuing */
 					FORM_PUTC(' ');
 				}
@@ -901,6 +917,10 @@ static void format_and_quote_body(FORM *form, const char *body, int addquotes)
 					int linelen = line_len(s);
 					in_quotes = 0;
 					client_debug(10, "Quote depth of row %d is %d (%d chars left on line)", row, quote_depth, linelen);
+					/* It doesn't start with space, add one for readability */
+					if (*s != ' ') {
+						FORM_PUTC(' ');
+					}
 				}
 			}
 			if (addquotes && inputcol == 0 && quote_depth == 0) {
@@ -2093,7 +2113,7 @@ static int __editor(struct client *client, struct pollfd *pfds, uint32_t uid, st
 			if (res < 0) {
 				goto done;
 			} else if (res > 0) {
-				client_set_status_nout(client, msgc.error[0] ? msgc.error : "Error sending message");
+				client_set_status_nout(client, msgc.error[0] ? msgc.error : res == 2 ? "Sent, error saving message" : "Error sending message");
 				beep();
 				if (needresize) {
 					goto resize;

evergreen.c

@@ -1238,7 +1238,7 @@ static void adjust_start_seqno(struct client *client, uint32_t current, int offs
 		/* Going up */
 		uint32_t max_start_seqno;
 
-		if (client->sel_mbox->total > FETCHLIST_INTERVAL) {
+		if (client->sel_mbox->total > (uint32_t) FETCHLIST_INTERVAL) {
 			max_start_seqno = client->sel_mbox->total - FETCHLIST_INTERVAL;
 		} else {
 			max_start_seqno = 1;

evergreen.h

@@ -37,7 +37,7 @@
  * In return, more messages can be scrolled at once without
  * having to re-download another set of headers.
  */
-#define FETCHLIST_INTERVAL 180
+#define FETCHLIST_INTERVAL (2 * LINES)
 
 /* Window dimension settings */
 #define MIN_COLS_FOR_EXPANDED_LIST_INFO 97

imap.c

@@ -2298,6 +2298,10 @@ static int client_flush_pending_output(struct client *client)
 			line = mailimap_read_line(client->imap);
 			/* Read and discard */
 			client_debug(1, "Flushing output '%s'", line);
+			if (strlen_zero(line)) {
+				/* Avoid infinite loop if we keep reading nothing */
+				break;
+			}
 		} else {
 			break;
 		}
@@ -2879,6 +2883,8 @@ static int __handle_store(struct client *client, int sign, struct mailimap_set *
 	int res;
 	struct mailimap_store_att_flags *att_flags;
 
+	assert(!client->idling);
+
 	if (sign > 0) {
 		att_flags = mailimap_store_att_flags_new_add_flags_silent(flag_list);
 	} else {
@@ -2909,6 +2915,8 @@ int client_store(struct client *client, int sign, struct message *msg, int flags
 	struct mailimap_flag_list *flag_list;
 	struct mailimap_set *set;
 
+	assert(!client->idling);
+
 	if (msg) {
 		set = mailimap_set_new_single(msg->uid);
 	} else {
@@ -2954,6 +2962,8 @@ int client_store_keyword(struct client *client, int sign, struct message *msg, c
 	char *keyword_dup = NULL;
 	struct mailimap_flag *flag;
 
+	assert(!client->idling);
+
 	if (msg) {
 		set = mailimap_set_new_single(msg->uid);
 	} else {
@@ -2993,6 +3003,8 @@ int client_copy(struct client *client, struct message *msg, const char *newmbox)
 	int res;
 	struct mailimap_set *set;
 
+	assert(!client->idling);
+
 	client_debug(3, "=> COPY %u %s\n", msg->uid, newmbox);
 	set = mailimap_set_new_single(msg->uid);
 	if (!set) {
@@ -3013,6 +3025,8 @@ int client_move(struct client *client, struct message *msg, const char *newmbox)
 	int res;
 	struct mailimap_set *set;
 
+	assert(!client->idling);
+
 	client_debug(3, "=> MOVE %u %s", msg->uid, newmbox);
 	set = mailimap_set_new_single(msg->uid);
 	if (!set) {
@@ -3041,6 +3055,7 @@ int client_move(struct client *client, struct message *msg, const char *newmbox)
 
 int client_expunge(struct client *client)
 {
+	assert(!client->idling);
 	return mailimap_expunge(client->imap);
 }
 
@@ -3049,6 +3064,8 @@ int client_append(struct client *client, const char *mailbox, int flags, const c
 	int res;
 	struct mailimap_flag_list *flag_list;
 
+	assert(!client->idling);
+
 	/* Automark anything we upload as \Seen */
 	flag_list = mailimap_flag_list_new_empty();
 	if (flags & IMAP_MESSAGE_FLAG_SEEN) {
@@ -3059,6 +3076,7 @@ int client_append(struct client *client, const char *mailbox, int flags, const c
 	}
 
 	res = mailimap_append(client->imap, mailbox, flag_list, NULL, msg, len);
+	mailimap_flag_list_free(flag_list);
 	if (res != MAILIMAP_NO_ERROR) {
 		client_warning("APPEND failed: %s", maildriver_strerror(res));
 		return -1;

smtp.c

@@ -68,6 +68,14 @@ static int add_recipients(struct message_constructor *msgc, struct mailsmtp *smt
 					client_debug(3, "Malformed recipient?");
 					continue;
 				}
+				/* mailesmtp_rcpt does not want <> surrounding the address, strip em here */
+				*recipient++ = '\0';
+				tmp = strchr(recipient, '>');
+				if (!tmp) {
+					client_debug(3, "Malformed recipient?");
+					continue;
+				}
+				*tmp = '\0';
 			} else {
 				/* The spaces we trimmed must have been at the end */
 			}

viewer.c

@@ -209,6 +209,10 @@ static int pad_add(WINDOW *pad, const char *restrict data, size_t len, int flags
 			client_debug(1, "WARNING: Parsed NUL character in message output?");
 			break;
 		}
+#if 0
+		/* Extra extra debug for assertion failures: */
+		client_debug(5, "outputcol is %d, at row %d, col %d (char %d: '%c')", outputcol, y, x, *c, isprint(*c) ? *c : ' ');
+#endif
 		if (x != outputcol) {
 			client_debug(1, "WARNING! outputcol is %d, but actually at row %d, col %d? (char %d: '%c')", outputcol, y, x, *c, isprint(*c) ? *c : ' ');
 			if (*c <= 127) {
@@ -228,7 +232,7 @@ static int pad_add(WINDOW *pad, const char *restrict data, size_t len, int flags
 				was_unicode = 0;
 			}
 		} else {
-			was_unicode = 0;
+			was_unicode = *c >= 128;
 		}
 		if (*c == '\r') {
 			outputcol--; /* We're not drawing anything, and loop post will increment again */