[PATCH v2 02/11] cli: Separate current and deprecated format version

[Austin Clements <amdragon@MIT.EDU>]

Previously, the CLI would print a deprecation warning if a client
requested any format version other than the current one.  However, if
we add fields that are backwards-compatible, but want clients to be
able to depend on, we need to bump the version, but that doesn't make
the older version deprecated.

Hence, separate out the "minimum active" version and only print a
warning for requests below this version number.
---
 notmuch-client.h | 6 ++++++
 notmuch.c        | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/notmuch-client.h b/notmuch-client.h
index 0bfa4da..4ecb3ae 100644
--- a/notmuch-client.h
+++ b/notmuch-client.h
@@ -142,6 +142,12 @@ chomp_newline (char *str)
 /* The minimum supported structured output format version.  Requests
  * for format versions below this will return an error. */
 #define NOTMUCH_FORMAT_MIN 1
+/* The minimum non-deprecated structured output format version.
+ * Requests for format versions below this will print a stern warning.
+ * Must be between NOTMUCH_FORMAT_MIN and NOTMUCH_FORMAT_CUR,
+ * inclusive.
+ */
+#define NOTMUCH_FORMAT_MIN_ACTIVE 1
 
 /* The output format version requested by the caller on the command
  * line.  If no format version is requested, this will be set to
diff --git a/notmuch.c b/notmuch.c
index 8d303a1..54f46c6 100644
--- a/notmuch.c
+++ b/notmuch.c
@@ -127,7 +127,7 @@ by the notmuch CLI (it requires at least version %d).  You may need to\n\
 upgrade your notmuch front-end.\n",
 		 notmuch_format_version, NOTMUCH_FORMAT_MIN);
 	exit (NOTMUCH_EXIT_FORMAT_TOO_OLD);
-    } else if (notmuch_format_version != NOTMUCH_FORMAT_CUR) {
+    } else if (notmuch_format_version < NOTMUCH_FORMAT_MIN_ACTIVE) {
 	/* Warn about old version requests so compatibility issues are
 	 * less likely when we drop support for a deprecated format
 	 * versions. */
-- 
1.8.4.rc3