Shared reusable client for RM_Call() (#8516)

A single client pointer is added in the server struct. This is
initialized by the first RM_Call() and reused for every subsequent
RM_Call() except if it's already in use, which means that it's not
used for (recursive) module calls to modules. For these, a new
"fake" client is created each time.

Other changes:
* Avoid allocating a dict iterator in pubsubUnsubscribeAllChannels
  when not needed

1 files changed, 5 insertions, 0 deletions

diff --git a/tests/unit/moduleapi/misc.tcl b/tests/unit/moduleapi/misc.tcl
index d60ccca8f..b5cd6100c 100644
--- a/tests/unit/moduleapi/misc.tcl
+++ b/tests/unit/moduleapi/misc.tcl
@@ -16,6 +16,11 @@ start_server {tags {"modules"}} {
         assert { [string match "*cmdstat_module*" $info] }
     }
 
+    test {test RM_Call recursive} {
+        set info [r test.call_generic test.call_generic info commandstats]
+        assert { [string match "*cmdstat_module*" $info] }
+    }
+
     test {test redis version} {
         set version [s redis_version]
         assert_equal $version [r test.redisversion]