protocol: introduce protocol extension mechanisms

diff --git a/cache.h b/cache.h
index 49b083ee0a10ea379f271e141ccee0fa852a1954..c74b7367191ed05717bd22697ad9ac4ca747f714 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -445,6 +445,14 @@ static inline enum object_type object_type(unsigned int mode)
 #define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
 #define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
 
+/*
+ * Environment variable used in handshaking the wire protocol.
+ * Contains a colon ':' separated list of keys with optional values
+ * 'key[=value]'.  Presence of unknown keys and values must be
+ * ignored.
+ */
+#define GIT_PROTOCOL_ENVIRONMENT "GIT_PROTOCOL"
+
 /*
  * This environment variable is expected to contain a boolean indicating
  * whether we should or should not treat: