[PATCH 3/7] show: Support --format-version

[Austin Clements <amdragon@MIT.EDU>]

---
 man/man1/notmuch-show.1 |   20 ++++++++++++++++++++
 notmuch-show.c          |    3 +++
 2 files changed, 23 insertions(+)

diff --git a/man/man1/notmuch-show.1 b/man/man1/notmuch-show.1
index bd41c48..44cec46 100644
--- a/man/man1/notmuch-show.1
+++ b/man/man1/notmuch-show.1
@@ -128,6 +128,15 @@ message.
 
 .RS 4
 .TP 4
+.BR \-\-format-version=N
+
+Use the specified structured output format version.  This is intended
+for programs that invoke \fBnotmuch\fR(1) internally.  If omitted, the
+latest supported version will be used.
+.RE
+
+.RS 4
+.TP 4
 .B \-\-part=N
 
 Output the single decoded MIME part N of a single message.  The search
@@ -201,6 +210,17 @@ column of output from the
 .B notmuch search
 command.
 
+.SH EXIT STATUS
+
+This command supports the following special exit status codes
+
+.TP
+.B 20
+The requested format version is too old.
+.TP
+.B 21
+The requested format version is too new.
+
 .SH SEE ALSO
 
 \fBnotmuch\fR(1), \fBnotmuch-config\fR(1), \fBnotmuch-count\fR(1),
diff --git a/notmuch-show.c b/notmuch-show.c
index a83fef9..39faf21 100644
--- a/notmuch-show.c
+++ b/notmuch-show.c
@@ -1066,6 +1066,7 @@ notmuch_show_command (void *ctx, unused (int argc), unused (char *argv[]))
 				  { "mbox", NOTMUCH_FORMAT_MBOX },
 				  { "raw", NOTMUCH_FORMAT_RAW },
 				  { 0, 0 } } },
+	{ NOTMUCH_OPT_INT, &notmuch_format_version, "format-version", 0, 0 },
 	{ NOTMUCH_OPT_KEYWORD, &exclude, "exclude", 'x',
 	  (notmuch_keyword_t []){ { "true", EXCLUDE_TRUE },
 				  { "false", EXCLUDE_FALSE },
@@ -1128,6 +1129,8 @@ notmuch_show_command (void *ctx, unused (int argc), unused (char *argv[]))
 	break;
     }
 
+    notmuch_exit_if_unsupported_format ();
+
     /* Default is entire-thread = FALSE except for format=json and
      * format=sexp. */
     if (entire_thread == ENTIRE_THREAD_DEFAULT) {
-- 
1.7.10.4