func_channel.c: Update MASTER_CHANNEL documentation

Be more explicit in what is meant by the master channel to eliminate
misunderstanding.

ASTERISK-23133

Change-Id: I453bcaf4b99404a5a3e345dbf093ac6c1afcfc72

diff --git a/funcs/func_channel.c b/funcs/func_channel.c
index 3005d31b120008d6ff7fd30ec4df6faef717abd6..793ea3f891cc7d4ee053dc76d566b52f0d78b9b4 100644 (file)
--- a/funcs/func_channel.c
+++ b/funcs/func_channel.c
@@ -69,8 +69,11 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
                        Gets or sets variables on the master channel
                </synopsis>
                <description>
-                       <para>Allows access to the channel which created the current channel, if any.  If the channel is already
-                       a master channel, then accesses local channel variables.</para>
+                       <para>Allows access to the oldest channel associated with the current
+                       channel if it still exists.  If the channel is the master channel or
+                       the master channel no longer exists then access local channel variables
+                       instead.  In other words, the master channel is the channel identified by
+                       the channel's linkedid.</para>
                </description>
        </function>
        <function name="CHANNEL" language="en_US">