[PATCH] cli: avoid non-zero exits in notmuch insert --keep

[Maarten Aertsen <sagi-notmuch@rtsn.nl>]

Re-ordered code that touches the database to try and deliver e-mail to
at least try to deliver to the Maildir (which, with --keep should return
success).

In the case of any failure, we now return EX_TEMPFAIL (a sendmail
convention, defined in sysexits.h) to signal to the LDA that it should
retry later. This prevents a direct reject or bounce of e-mail.
---
 notmuch-client.h |  1 +
 notmuch-insert.c | 42 +++++++++++++++++++++++-------------------
 notmuch.c        | 17 +++++++++++++----
 3 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/notmuch-client.h b/notmuch-client.h
index 18e6c60..e3d6a46 100644
--- a/notmuch-client.h
+++ b/notmuch-client.h
@@ -466,6 +466,7 @@ print_status_query (const char *loc,
 
 extern char *notmuch_requested_db_uuid;
 extern const notmuch_opt_desc_t  notmuch_shared_options [];
+notmuch_bool_t notmuch_has_unmatched_db_uuid (notmuch_database_t *notmuch);
 void notmuch_exit_if_unmatched_db_uuid (notmuch_database_t *notmuch);
 
 void notmuch_process_shared_options (const char* subcommand_name);
diff --git a/notmuch-insert.c b/notmuch-insert.c
index 5205c17..35b6779 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -28,6 +28,8 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include <sysexits.h>
+
 static volatile sig_atomic_t interrupted;
 
 static void
@@ -532,31 +534,33 @@ notmuch_insert_command (notmuch_config_t *config, int argc, char *argv[])
     action.sa_flags = 0;
     sigaction (SIGINT, &action, NULL);
 
-    if (notmuch_database_open (notmuch_config_get_database_path (config),
-			       NOTMUCH_DATABASE_MODE_READ_WRITE, &notmuch))
-	return EXIT_FAILURE;
-
-    notmuch_exit_if_unmatched_db_uuid (notmuch);
-
     /* Write the message to the Maildir new directory. */
     newpath = maildir_write_new (config, STDIN_FILENO, maildir);
     if (! newpath) {
-	notmuch_database_destroy (notmuch);
 	return EXIT_FAILURE;
     }
 
-    /* Index the message. */
-    status = add_file (notmuch, newpath, tag_ops, synchronize_flags, keep);
-
-    /* Commit changes. */
-    close_status = notmuch_database_destroy (notmuch);
-    if (close_status) {
-	/* Hold on to the first error, if any. */
-	if (! status)
-	    status = close_status;
-	fprintf (stderr, "%s: failed to commit database changes: %s\n",
-		 keep ? "Warning" : "Error",
-		 notmuch_status_to_string (close_status));
+    status = notmuch_database_open (notmuch_config_get_database_path (config),
+			       NOTMUCH_DATABASE_MODE_READ_WRITE, &notmuch);
+    if (! status) {
+	/* with keep, send EX_TEMPFAIL per sysexits.h to invite the caller to
+	 * retry at some later point and avoid permanent failure */
+	if (notmuch_has_unmatched_db_uuid(notmuch))
+            exit (keep ? EX_TEMPFAIL : EXIT_FAILURE);
+
+        /* Index the message. */
+        status = add_file (notmuch, newpath, tag_ops, synchronize_flags, keep);
+
+        /* Commit changes. */
+        close_status = notmuch_database_destroy (notmuch);
+        if (close_status) {
+            /* Hold on to the first error, if any. */
+            if (! status)
+                status = close_status;
+            fprintf (stderr, "%s: failed to commit database changes: %s\n",
+                keep ? "Warning" : "Error",
+                notmuch_status_to_string (close_status));
+	}
     }
 
     if (status) {
diff --git a/notmuch.c b/notmuch.c
index ce6c575..783bb2a 100644
--- a/notmuch.c
+++ b/notmuch.c
@@ -220,20 +220,29 @@ be supported in the future.\n", notmuch_format_version);
     }
 }
 
-void
-notmuch_exit_if_unmatched_db_uuid (notmuch_database_t *notmuch)
+notmuch_bool_t
+notmuch_has_unmatched_db_uuid (notmuch_database_t *notmuch)
 {
     const char *uuid = NULL;
 
     if (!notmuch_requested_db_uuid)
-	return;
+	return FALSE;
     IGNORE_RESULT (notmuch_database_get_revision (notmuch, &uuid));
 
     if (strcmp (notmuch_requested_db_uuid, uuid) != 0){
 	fprintf (stderr, "Error: requested database revision %s does not match %s\n",
 		 notmuch_requested_db_uuid, uuid);
-	exit (1);
+	return TRUE;
     }
+
+    return FALSE;
+}
+
+void
+notmuch_exit_if_unmatched_db_uuid (notmuch_database_t *notmuch)
+{
+    if (notmuch_has_unmatched_db_uuid(notmuch))
+	exit (1);
 }
 
 static void
-- 
2.7.0