From 775e4cecff88095155500bb29f3a240acfe64dec Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Wed, 17 Oct 2018 19:09:36 +0200
Subject: [PATCH] pgraph: fix freeze in garbage_collect(), esp. when rate-limit
 is on

---
 panda/src/pgraph/renderAttrib.cxx   | 5 ++++-
 panda/src/pgraph/renderState.cxx    | 3 +++
 panda/src/pgraph/transformState.cxx | 3 +++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/panda/src/pgraph/renderAttrib.cxx b/panda/src/pgraph/renderAttrib.cxx
index 73b1e4b392..9bac4e666a 100644
--- a/panda/src/pgraph/renderAttrib.cxx
+++ b/panda/src/pgraph/renderAttrib.cxx
@@ -211,7 +211,7 @@ garbage_collect() {
   }
 
   num_this_pass = std::min(num_this_pass, size);
-  size_t stop_at_element = (_garbage_index + num_this_pass) % size;
+  size_t stop_at_element = (si + num_this_pass) % size;
 
   do {
     RenderAttrib *attrib = (RenderAttrib *)_attribs->get_key(si);
@@ -229,6 +229,9 @@ garbage_collect() {
       // still need to visit.
       --size;
       --si;
+      if (stop_at_element > 0) {
+        --stop_at_element;
+      }
     }
 
     si = (si + 1) % size;
diff --git a/panda/src/pgraph/renderState.cxx b/panda/src/pgraph/renderState.cxx
index 927d1e7073..5ce1527247 100644
--- a/panda/src/pgraph/renderState.cxx
+++ b/panda/src/pgraph/renderState.cxx
@@ -950,6 +950,9 @@ garbage_collect() {
       // still need to visit.
       --size;
       --si;
+      if (stop_at_element > 0) {
+        --stop_at_element;
+      }
     }
 
     si = (si + 1) % size;
diff --git a/panda/src/pgraph/transformState.cxx b/panda/src/pgraph/transformState.cxx
index 453fb505b4..4d02425683 100644
--- a/panda/src/pgraph/transformState.cxx
+++ b/panda/src/pgraph/transformState.cxx
@@ -1216,6 +1216,9 @@ garbage_collect() {
       // still need to visit.
       --size;
       --si;
+      if (stop_at_element > 0) {
+        --stop_at_element;
+      }
     }
 
     si = (si + 1) % size;