From 4374185f2a13aede495e576df3e43c26d2d2c0e4 Mon Sep 17 00:00:00 2001
From: Andrei Litvin <andy314@gmail.com>
Date: Tue, 15 Mar 2022 17:10:11 -0400
Subject: [PATCH] Ensure ResolverProxy maintains callbacks until init is
 called. Ensure server  app always initializes the global resolver (#16230)

---
 src/app/server/Server.cpp     |  2 ++
 src/lib/dnssd/ResolverProxy.h | 28 +++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/app/server/Server.cpp b/src/app/server/Server.cpp
index 229b4786c648a0..949affe999294d 100644
--- a/src/app/server/Server.cpp
+++ b/src/app/server/Server.cpp
@@ -197,6 +197,8 @@ CHIP_ERROR Server::Init(AppDelegate * delegate, uint16_t secureServicePort, uint
     err = chip::app::InteractionModelEngine::GetInstance()->Init(&mExchangeMgr);
     SuccessOrExit(err);
 
+    chip::Dnssd::Resolver::Instance().Init(DeviceLayer::UDPEndPointManager());
+
 #if CHIP_CONFIG_ENABLE_SERVER_IM_EVENT
     // Initialize event logging subsystem
     {
diff --git a/src/lib/dnssd/ResolverProxy.h b/src/lib/dnssd/ResolverProxy.h
index 00bb397a9cd4f0..57690c2dbb7920 100644
--- a/src/lib/dnssd/ResolverProxy.h
+++ b/src/lib/dnssd/ResolverProxy.h
@@ -86,6 +86,24 @@ class ResolverProxy : public Resolver
         ReturnErrorOnFailure(chip::Dnssd::Resolver::Instance().Init(udpEndPoint));
         VerifyOrReturnError(mDelegate == nullptr, CHIP_ERROR_INCORRECT_STATE);
         mDelegate = chip::Platform::New<ResolverDelegateProxy>();
+
+        if (mDelegate != nullptr)
+        {
+            if (mPreInitOperationalDelegate != nullptr)
+            {
+                ChipLogProgress(Discovery, "Setting operational delegate post init");
+                mDelegate->SetOperationalDelegate(mPreInitOperationalDelegate);
+                mPreInitOperationalDelegate = nullptr;
+            }
+
+            if (mPreInitCommissioningDelegate != nullptr)
+            {
+                ChipLogProgress(Discovery, "Setting commissioning delegate post init");
+                mDelegate->SetCommissioningDelegate(mPreInitCommissioningDelegate);
+                mPreInitCommissioningDelegate = nullptr;
+            }
+        }
+
         return mDelegate != nullptr ? CHIP_NO_ERROR : CHIP_ERROR_NO_MEMORY;
     }
 
@@ -97,7 +115,8 @@ class ResolverProxy : public Resolver
         }
         else
         {
-            ChipLogError(Discovery, "Failed to proxy operational discovery: missing delegate");
+            ChipLogProgress(Discovery, "Delaying proxy of operational discovery: missing delegate");
+            mPreInitOperationalDelegate = delegate;
         }
     }
 
@@ -109,7 +128,8 @@ class ResolverProxy : public Resolver
         }
         else
         {
-            ChipLogError(Discovery, "Failed to proxy commissioning discovery: missing delegate");
+            ChipLogError(Discovery, "Delaying proxy of commissioning discovery: missing delegate");
+            mPreInitCommissioningDelegate = delegate;
         }
     }
 
@@ -127,7 +147,9 @@ class ResolverProxy : public Resolver
     CHIP_ERROR FindCommissioners(DiscoveryFilter filter = DiscoveryFilter()) override;
 
 private:
-    ResolverDelegateProxy * mDelegate = nullptr;
+    ResolverDelegateProxy * mDelegate                            = nullptr;
+    OperationalResolveDelegate * mPreInitOperationalDelegate     = nullptr;
+    CommissioningResolveDelegate * mPreInitCommissioningDelegate = nullptr;
 };
 
 } // namespace Dnssd