From 23b364147658bd7f66a317159cc9fdba8bbb0ee8 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Tue, 16 Apr 2024 12:50:40 -0700
Subject: [PATCH] [mle] restart role transition timeout from
 `SetRouterEligible(true)` (#10033)

Updates `MleRouter::SetRouterEligible()` to restart the role transition
timer if the device is a child and the router eligibility is changed
to `true`.
---
 src/core/thread/mle_router.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index b55341f9b..26c6541e7 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -157,7 +157,12 @@ Error MleRouter::SetRouterEligible(bool aEligible)
 {
     Error error = kErrorNone;
 
-    VerifyOrExit(IsFullThreadDevice() || !aEligible, error = kErrorNotCapable);
+    if (!IsFullThreadDevice())
+    {
+        VerifyOrExit(!aEligible, error = kErrorNotCapable);
+    }
+
+    VerifyOrExit(aEligible != mRouterEligible);
 
     mRouterEligible = aEligible;
 
@@ -168,6 +173,11 @@ Error MleRouter::SetRouterEligible(bool aEligible)
         break;
 
     case kRoleChild:
+        if (mRouterEligible)
+        {
+            mRouterRoleTransition.StartTimeout();
+        }
+
         Get<Mac::Mac>().SetBeaconEnabled(mRouterEligible);
         break;