From c0cd6528b7f26276f25a712a92996e9cba204611 Mon Sep 17 00:00:00 2001
From: Karan <kvish2012@gmail.com>
Date: Fri, 15 Feb 2019 20:36:31 -0800
Subject: [PATCH] dont evaluate existing reservations against new ports (#2928)

---
 .../offer/evaluate/TaskResourceMapper.java    | 21 ++++++++++++-------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/sdk/scheduler/src/main/java/com/mesosphere/sdk/offer/evaluate/TaskResourceMapper.java b/sdk/scheduler/src/main/java/com/mesosphere/sdk/offer/evaluate/TaskResourceMapper.java
index f4efd5edb19..b751abb971b 100644
--- a/sdk/scheduler/src/main/java/com/mesosphere/sdk/offer/evaluate/TaskResourceMapper.java
+++ b/sdk/scheduler/src/main/java/com/mesosphere/sdk/offer/evaluate/TaskResourceMapper.java
@@ -158,14 +158,19 @@ private Optional<ResourceLabels> findMatchingPortSpec(
       PortSpec portSpec = (PortSpec) resourceSpec;
       if (portSpec.getPort() == 0) {
         // For dynamic ports, we need to detect the port value that we had selected.
-        return taskPortFinder.getPriorPort(portSpec)
-            .filter(priorTaskPort -> RangeUtils.isInAny(ranges.getRangeList(), priorTaskPort))
-            .map(ignored -> new ResourceLabels(
-                resourceSpec,
-                resourceId.get(),
-                ResourceMapperUtils.getNamespaceLabel(
-                    ResourceUtils.getNamespace(taskResource),
-                    resourceNamespace)));
+        Optional<Long> priorPort = taskPortFinder.getPriorPort(portSpec);
+        if (!priorPort.isPresent()) {
+          //this is a new portSpec and will never match a previously reserved taskResource
+          continue;
+        }
+        return priorPort
+              .filter(priorTaskPort -> RangeUtils.isInAny(ranges.getRangeList(), priorTaskPort))
+              .map(ignored -> new ResourceLabels(
+                  resourceSpec,
+                  resourceId.get(),
+                  ResourceMapperUtils.getNamespaceLabel(
+                      ResourceUtils.getNamespace(taskResource),
+                      resourceNamespace)));
       } else if (RangeUtils.isInAny(ranges.getRangeList(), portSpec.getPort())) {
         // For fixed ports, we can just check for a resource whose ranges include that port.
         return Optional.of(new ResourceLabels(