processAssignVar optimization for arrays

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -5078,7 +5078,30 @@ private function processAssignVar(
 			$offsetNativeValueType = $varNativeType;
 
 			$valueToWrite = $this->produceArrayDimFetchAssignValueToWrite($offsetTypes, $offsetValueType, $valueToWrite);
-			$nativeValueToWrite = $this->produceArrayDimFetchAssignValueToWrite($offsetNativeTypes, $offsetNativeValueType, $nativeValueToWrite);
+
+			$nativeValueToWrite = $valueToWrite;
+			if (!$offsetValueType->equals($offsetNativeValueType) || !$valueToWrite->equals($nativeValueToWrite)) {
+				$nativeValueToWrite = $this->produceArrayDimFetchAssignValueToWrite($offsetNativeTypes, $offsetNativeValueType, $nativeValueToWrite);
+			} else {
+				foreach ($offsetTypes as $i => $offsetType) {
+					$offsetNativeType = $offsetNativeTypes[$i];
+					if ($offsetType === null) {
+						if ($offsetNativeType !== null) {
+							throw new ShouldNotHappenException();
+						}
+
+						continue;
+					} elseif ($offsetNativeType === null) {
+						throw new ShouldNotHappenException();
+					}
+					if ($offsetType->equals($offsetNativeType)) {
+						continue;
+					}
+
+					$nativeValueToWrite = $this->produceArrayDimFetchAssignValueToWrite($offsetNativeTypes, $offsetNativeValueType, $nativeValueToWrite);
+					break;
+				}
+			}
 
 			if ($varType->isArray()->yes() || !(new ObjectType(ArrayAccess::class))->isSuperTypeOf($varType)->yes()) {
 				if ($var instanceof Variable && is_string($var->name)) {