Core/Entities: Instead of clearing all unit movementflags on SetRoot and SetStunned, only remove ones that are confirmed to be conflicting with MOVEMENTFLAG_ROOT. Fixes vehicle passenger visuals.

Closes #2141

2 files changed, 9 insertions, 5 deletions

diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 995eaed8797..ff598119c37 100755
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -15620,10 +15620,12 @@ void Unit::SetStunned(bool apply)
         SetUInt64Value(UNIT_FIELD_TARGET, 0);
         SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_STUNNED);
 
-        // MOVEMENTFLAG_ROOT cannot be used in conjunction with ie. MOVEMENTFLAG_FORWARD,
+        // MOVEMENTFLAG_ROOT cannot be used in conjunction with
+        // MOVEMENTFLAG_FORWARD, MOVEMENTFLAG_BACKWARD, MOVEMENTFLAG_STRAFE_LEFT, MOVEMENTFLAG_STRAFE RIGHT (tested 3.3.5a)
         // this will freeze clients. That's why we remove any current movement flags before
         // setting MOVEMENTFLAG_ROOT
-        SetUnitMovementFlags(MOVEMENTFLAG_ROOT);
+        RemoveUnitMovementFlag(MOVEMENTFLAG_FORWARD | MOVEMENTFLAG_BACKWARD | MOVEMENTFLAG_STRAFE_LEFT | MOVEMENTFLAG_STRAFE_RIGHT);
+        AddUnitMovementFlag(MOVEMENTFLAG_ROOT);
 
         // Creature specific
         if (GetTypeId() != TYPEID_PLAYER)
@@ -15667,10 +15669,12 @@ void Unit::SetRooted(bool apply)
         if (m_rootTimes > 0) // blizzard internal check?
             m_rootTimes++;
 
-        // MOVEMENTFLAG_ROOT cannot be used in conjunction with ie. MOVEMENTFLAG_FORWARD,
+        // MOVEMENTFLAG_ROOT cannot be used in conjunction with
+        // MOVEMENTFLAG_FORWARD, MOVEMENTFLAG_BACKWARD, MOVEMENTFLAG_STRAFE_LEFT, MOVEMENTFLAG_STRAFE RIGHT (tested 3.3.5a)
         // this will freeze clients. That's why we remove any current movement flags before
         // setting MOVEMENTFLAG_ROOT
-        SetUnitMovementFlags(MOVEMENTFLAG_ROOT);
+        RemoveUnitMovementFlag(MOVEMENTFLAG_FORWARD | MOVEMENTFLAG_BACKWARD | MOVEMENTFLAG_STRAFE_LEFT | MOVEMENTFLAG_STRAFE_RIGHT);
+        AddUnitMovementFlag(MOVEMENTFLAG_ROOT);
 
         if (GetTypeId() == TYPEID_PLAYER)
         {
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 52e85b2e3db..3f3fb08b50b 100755
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -643,7 +643,7 @@ enum MovementFlags
     MOVEMENTFLAG_WALKING               = 0x00000100,               // Walking
     MOVEMENTFLAG_ONTRANSPORT           = 0x00000200,               // Used for flying on some creatures
     MOVEMENTFLAG_LEVITATING            = 0x00000400,
-    MOVEMENTFLAG_ROOT                  = 0x00000800,
+    MOVEMENTFLAG_ROOT                  = 0x00000800,               // Must not be set along with MOVEMENTFLAG_FORWARD | MOVEMENTFLAG_BACKWARD | MOVEMENTFLAG_STRAFE_LEFT | MOVEMENTFLAG_STRAFE_RIGHT -> client freeze
     MOVEMENTFLAG_JUMPING               = 0x00001000,
     MOVEMENTFLAG_FALLING               = 0x00002000,               // damage dealt on that type of falling
     MOVEMENTFLAG_PENDING_STOP          = 0x00004000,