imap-send: create target mailbox if it is missing

Some MUAs delete their "drafts" folder when it is empty, so
git imap-send should be able to create it if necessary.

This change checks that the folder exists immediately after
login and tries to create it if it is missing.

There was some vestigial code to handle a [TRYCREATE] response
from the server when an APPEND target is missing. However this
code never ran (the create and trycreate flags were never set)
and when I tried to make it run I found that the code had already
thrown away the contents of the message it was trying to append.

Signed-off-by: Tony Finch <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: fanf2

imap-send.c

@@ -128,7 +128,6 @@ struct imap_cmd_cb {
 	char *data;
 	int dlen;
 	int uid;
-	unsigned create:1, trycreate:1;
 };
 
 struct imap_cmd {
@@ -493,9 +492,9 @@ static int nfsnprintf(char *buf, int blen, const char *fmt, ...)
 	return ret;
 }
 
-static struct imap_cmd *v_issue_imap_cmd(struct imap_store *ctx,
-					 struct imap_cmd_cb *cb,
-					 const char *fmt, va_list ap)
+static struct imap_cmd *issue_imap_cmd(struct imap_store *ctx,
+				       struct imap_cmd_cb *cb,
+				       const char *fmt, va_list ap)
 {
 	struct imap *imap = ctx->imap;
 	struct imap_cmd *cmd;
@@ -558,20 +557,6 @@ static struct imap_cmd *v_issue_imap_cmd(struct imap_store *ctx,
 	return cmd;
 }
 
-__attribute__((format (printf, 3, 4)))
-static struct imap_cmd *issue_imap_cmd(struct imap_store *ctx,
-				       struct imap_cmd_cb *cb,
-				       const char *fmt, ...)
-{
-	struct imap_cmd *ret;
-	va_list ap;
-
-	va_start(ap, fmt);
-	ret = v_issue_imap_cmd(ctx, cb, fmt, ap);
-	va_end(ap);
-	return ret;
-}
-
 __attribute__((format (printf, 3, 4)))
 static int imap_exec(struct imap_store *ctx, struct imap_cmd_cb *cb,
 		     const char *fmt, ...)
@@ -580,7 +565,7 @@ static int imap_exec(struct imap_store *ctx, struct imap_cmd_cb *cb,
 	struct imap_cmd *cmdp;
 
 	va_start(ap, fmt);
-	cmdp = v_issue_imap_cmd(ctx, cb, fmt, ap);
+	cmdp = issue_imap_cmd(ctx, cb, fmt, ap);
 	va_end(ap);
 	if (!cmdp)
 		return RESP_BAD;
@@ -596,7 +581,7 @@ static int imap_exec_m(struct imap_store *ctx, struct imap_cmd_cb *cb,
 	struct imap_cmd *cmdp;
 
 	va_start(ap, fmt);
-	cmdp = v_issue_imap_cmd(ctx, cb, fmt, ap);
+	cmdp = issue_imap_cmd(ctx, cb, fmt, ap);
 	va_end(ap);
 	if (!cmdp)
 		return DRV_STORE_BAD;
@@ -714,8 +699,8 @@ static int parse_response_code(struct imap_store *ctx, struct imap_cmd_cb *cb,
 static int get_cmd_result(struct imap_store *ctx, struct imap_cmd *tcmd)
 {
 	struct imap *imap = ctx->imap;
-	struct imap_cmd *cmdp, **pcmdp, *ncmdp;
-	char *cmd, *arg, *arg1, *p;
+	struct imap_cmd *cmdp, **pcmdp;
+	char *cmd, *arg, *arg1;
 	int n, resp, resp2, tag;
 
 	for (;;) {
@@ -801,30 +786,9 @@ static int get_cmd_result(struct imap_store *ctx, struct imap_cmd *tcmd)
 			if (!strcmp("OK", arg))
 				resp = DRV_OK;
 			else {
-				if (!strcmp("NO", arg)) {
-					if (cmdp->cb.create && cmd && (cmdp->cb.trycreate || !memcmp(cmd, "[TRYCREATE]", 11))) { /* SELECT, APPEND or UID COPY */
-						p = strchr(cmdp->cmd, '"');
-						if (!issue_imap_cmd(ctx, NULL, "CREATE \"%.*s\"", (int)(strchr(p + 1, '"') - p + 1), p)) {
-							resp = RESP_BAD;
-							goto normal;
-						}
-						/* not waiting here violates the spec, but a server that does not
-						   grok this nonetheless violates it too. */
-						cmdp->cb.create = 0;
-						if (!(ncmdp = issue_imap_cmd(ctx, &cmdp->cb, "%s", cmdp->cmd))) {
-							resp = RESP_BAD;
-							goto normal;
-						}
-						free(cmdp->cmd);
-						free(cmdp);
-						if (!tcmd)
-							return 0;	/* ignored */
-						if (cmdp == tcmd)
-							tcmd = ncmdp;
-						continue;
-					}
+				if (!strcmp("NO", arg))
 					resp = RESP_NO;
-				} else /*if (!strcmp("BAD", arg))*/
+				else /*if (!strcmp("BAD", arg))*/
 					resp = RESP_BAD;
 				fprintf(stderr, "IMAP command '%s' returned response (%s) - %s\n",
 					 memcmp(cmdp->cmd, "LOGIN", 5) ?
@@ -833,7 +797,6 @@ static int get_cmd_result(struct imap_store *ctx, struct imap_cmd *tcmd)
 			}
 			if ((resp2 = parse_response_code(ctx, &cmdp->cb, cmd)) > resp)
 				resp = resp2;
-		normal:
 			if (cmdp->cb.done)
 				cmdp->cb.done(ctx, cmdp, resp);
 			free(cmdp->cb.data);
@@ -944,7 +907,7 @@ static int auth_cram_md5(struct imap_store *ctx, struct imap_cmd *cmd, const cha
 	return 0;
 }
 
-static struct imap_store *imap_open_store(struct imap_server_conf *srvc)
+static struct imap_store *imap_open_store(struct imap_server_conf *srvc, char *folder)
 {
 	struct credential cred = CREDENTIAL_INIT;
 	struct imap_store *ctx;
@@ -1156,6 +1119,25 @@ static struct imap_store *imap_open_store(struct imap_server_conf *srvc)
 		credential_approve(&cred);
 	credential_clear(&cred);
 
+	/* check the target mailbox exists */
+	ctx->name = folder;
+	switch (imap_exec(ctx, NULL, "EXAMINE \"%s\"", ctx->name)) {
+	case RESP_OK:
+		/* ok */
+		break;
+	case RESP_BAD:
+		fprintf(stderr, "IMAP error: could not check mailbox\n");
+		goto out;
+	case RESP_NO:
+		if (imap_exec(ctx, NULL, "CREATE \"%s\"", ctx->name) == RESP_OK) {
+			imap_info("Created missing mailbox\n");
+		} else {
+			fprintf(stderr, "IMAP error: could not create missing mailbox\n");
+			goto out;
+		}
+		break;
+	}
+
 	ctx->prefix = "";
 	return ctx;
 
@@ -1164,6 +1146,7 @@ static struct imap_store *imap_open_store(struct imap_server_conf *srvc)
 		credential_reject(&cred);
 	credential_clear(&cred);
 
+ out:
 	imap_close_store(ctx);
 	return NULL;
 }
@@ -1219,7 +1202,6 @@ static int imap_store_msg(struct imap_store *ctx, struct strbuf *msg)
 
 	box = ctx->name;
 	prefix = !strcmp(box, "INBOX") ? "" : ctx->prefix;
-	cb.create = 0;
 	ret = imap_exec_m(ctx, &cb, "APPEND \"%s%s\" ", prefix, box);
 	imap->caps = imap->rcaps;
 	if (ret != DRV_OK)
@@ -1422,14 +1404,13 @@ int main(int argc, char **argv)
 	}
 
 	/* write it to the imap server */
-	ctx = imap_open_store(&server);
+	ctx = imap_open_store(&server, imap_folder);
 	if (!ctx) {
 		fprintf(stderr, "failed to open store\n");
 		return 1;
 	}
 
 	fprintf(stderr, "sending %d message%s\n", total, (total != 1) ? "s" : "");
-	ctx->name = imap_folder;
 	while (1) {
 		unsigned percent = n * 100 / total;