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)) {