diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index 12672c9d53..a7db7e66cf 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -5384,12 +5384,12 @@ private function processAssignVar(
 				}
 
 				if ($dimExpr === null) {
-					$offsetTypes[] = null;
-					$offsetNativeTypes[] = null;
+					$offsetTypes[] = [null, TrinaryLogic::createYes()];
+					$offsetNativeTypes[] = [null, TrinaryLogic::createYes()];
 
 				} else {
-					$offsetTypes[] = $scope->getType($dimExpr);
-					$offsetNativeTypes[] = $scope->getNativeType($dimExpr);
+					$offsetTypes[] = [$scope->getType($dimExpr), $scope->getType($dimFetch->var)->hasOffsetValueType($scope->getType($dimExpr))->or($scope->hasExpressionType($dimFetch))];
+					$offsetNativeTypes[] = [$scope->getNativeType($dimExpr), $scope->getNativeType($dimFetch->var)->hasOffsetValueType($scope->getNativeType($dimExpr))->or($scope->hasExpressionType($dimFetch))];
 
 					if ($enterExpressionAssign) {
 						$scope->enterExpressionAssign($dimExpr);
@@ -5436,8 +5436,8 @@ private function processAssignVar(
 				$nativeValueToWrite = $this->produceArrayDimFetchAssignValueToWrite($offsetNativeTypes, $offsetNativeValueType, $nativeValueToWrite);
 			} else {
 				$rewritten = false;
-				foreach ($offsetTypes as $i => $offsetType) {
-					$offsetNativeType = $offsetNativeTypes[$i];
+				foreach ($offsetTypes as $i => [$offsetType]) {
+					[$offsetNativeType] = $offsetNativeTypes[$i];
 					if ($offsetType === null) {
 						if ($offsetNativeType !== null) {
 							throw new ShouldNotHappenException();
@@ -5489,6 +5489,26 @@ private function processAssignVar(
 						);
 					}
 				}
+
+				$arrayDimFetchVar = $originalVar;
+				while ($arrayDimFetchVar instanceof ArrayDimFetch) {
+					$dimExpr = $arrayDimFetchVar->dim;
+					if ($dimExpr === null) {
+						$arrayDimFetchVar = $arrayDimFetchVar->var;
+						continue;
+					}
+
+					$dimVar = $arrayDimFetchVar->var;
+					$dimVarType = $scope->getType($dimVar);
+					$dimDimType = $scope->getType($dimExpr);
+					if ($dimVarType->hasOffsetValueType($dimDimType)->yes()) {
+						$arrayDimFetchVar = $arrayDimFetchVar->var;
+						continue;
+					}
+
+					$scope = $scope->specifyExpressionType($arrayDimFetchVar, $scope->getType($arrayDimFetchVar), $scope->getNativeType($arrayDimFetchVar), TrinaryLogic::createYes());
+					$arrayDimFetchVar = $arrayDimFetchVar->var;
+				}
 			} else {
 				if ($var instanceof Variable) {
 					$nodeCallback(new VariableAssignNode($var, $assignedPropertyExpr, $isAssignOp), $scope);
@@ -5752,12 +5772,12 @@ static function (): void {
 	}
 
 	/**
-	 * @param list<Type|null> $offsetTypes
+	 * @param list<array{Type|null, TrinaryLogic}> $offsetTypes
 	 */
 	private function produceArrayDimFetchAssignValueToWrite(array $offsetTypes, Type $offsetValueType, Type $valueToWrite): Type
 	{
-		$offsetValueTypeStack = [$offsetValueType];
-		foreach (array_slice($offsetTypes, 0, -1) as $offsetType) {
+		$offsetValueTypeStack = [[$offsetValueType, TrinaryLogic::createYes()]];
+		foreach (array_slice($offsetTypes, 0, -1) as [$offsetType, $has]) {
 			if ($offsetType === null) {
 				$offsetValueType = new ConstantArrayType([], []);
 
@@ -5768,12 +5788,13 @@ private function produceArrayDimFetchAssignValueToWrite(array $offsetTypes, Type
 				}
 			}
 
-			$offsetValueTypeStack[] = $offsetValueType;
+			$offsetValueTypeStack[] = [$offsetValueType, $has];
 		}
 
-		foreach (array_reverse($offsetTypes) as $i => $offsetType) {
-			/** @var Type $offsetValueType */
-			$offsetValueType = array_pop($offsetValueTypeStack);
+		foreach (array_reverse($offsetTypes) as [$offsetType]) {
+			/** @var array{Type, TrinaryLogic} $stackItem */
+			$stackItem = array_pop($offsetValueTypeStack);
+			[$offsetValueType, $has] = $stackItem;
 			if (
 				!$offsetValueType instanceof MixedType
 				&& !$offsetValueType->isConstantArray()->yes()
@@ -5788,7 +5809,10 @@ private function produceArrayDimFetchAssignValueToWrite(array $offsetTypes, Type
 				}
 				$offsetValueType = TypeCombinator::intersect($offsetValueType, TypeCombinator::union(...$types));
 			}
-			$valueToWrite = $offsetValueType->setOffsetValueType($offsetType, $valueToWrite, $i === 0);
+			if (!$has->yes()) {
+				$offsetValueType = TypeCombinator::union($offsetValueType, new ConstantArrayType([], []));
+			}
+			$valueToWrite = $offsetValueType->setOffsetValueType($offsetType, $valueToWrite);
 		}
 
 		return $valueToWrite;
diff --git a/tests/PHPStan/Analyser/data/bug-10922.php b/tests/PHPStan/Analyser/data/bug-10922.php
index 62ee393f7b..036d49266f 100644
--- a/tests/PHPStan/Analyser/data/bug-10922.php
+++ b/tests/PHPStan/Analyser/data/bug-10922.php
@@ -12,7 +12,7 @@ public function sayHello(array $array): void
 		foreach ($array as $key => $item) {
 			$array[$key]['bar'] = '';
 		}
-		assertType("array<string, array{foo: string, bar: ''}>", $array);
+		assertType("array<string, array{foo: string, bar?: ''}>", $array);
 	}
 
 	/** @param array<string, array{foo: string}> $array */
@@ -38,6 +38,6 @@ public function sayHello3(array $array): void
 		foreach ($array as $key => $item) {
 			$array[$key]['bar'] = '';
 		}
-		assertType("non-empty-array<string, array{foo: string, bar: ''}>", $array);
+		assertType("non-empty-array<string, array{foo: string, bar?: ''}>", $array);
 	}
 }
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10025.php b/tests/PHPStan/Analyser/nsrt/bug-10025.php
new file mode 100644
index 0000000000..bd6637c531
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-10025.php
@@ -0,0 +1,25 @@
+<?php declare(strict_types = 1);
+
+namespace Bug10025;
+
+use function PHPStan\Testing\assertType;
+
+class MyClass {
+	public int $groupId;
+}
+
+/**
+ * @param list<MyClass> $foos
+ * @param list<MyClass> $bars
+ */
+function x(array $foos, array $bars): void {
+	$arr = [];
+	foreach ($foos as $foo) {
+		$arr[$foo->groupId]['foo'][] = $foo;
+	}
+	foreach ($bars as $bar) {
+		$arr[$bar->groupId]['bar'][] = $bar;
+	}
+
+	assertType('array<int, non-empty-array{foo?: non-empty-list<Bug10025\MyClass>, bar?: non-empty-list<Bug10025\MyClass>}>', $arr);
+}
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10089.php b/tests/PHPStan/Analyser/nsrt/bug-10089.php
new file mode 100644
index 0000000000..1756119067
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-10089.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace Bug10089;
+
+use function PHPStan\Testing\assertType;
+
+class Test
+{
+
+	protected function create_matrix(int $size): array
+	{
+		$size = min(8, $size);
+		$matrix = [];
+		for ($i = 0; $i < $size; $i++) {
+			$matrix[] = array_fill(0, $size, 0);
+		}
+
+		assertType('list<non-empty-list<0>>', $matrix);
+
+		$matrix[$size - 1][8] = 3;
+
+		assertType('non-empty-array<int, non-empty-array<int<0, max>, 0|3>>', $matrix);
+
+		return $matrix;
+	}
+
+}
+
+
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10640.php b/tests/PHPStan/Analyser/nsrt/bug-10640.php
new file mode 100644
index 0000000000..28388ab2c8
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-10640.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Bug10640;
+
+use function PHPStan\Testing\assertType;
+
+function (array $a, array $b): void {
+	$changes = [];
+	foreach ($a as $add) {
+		$changes[$add['id']]['add'][] = 1;
+	}
+	foreach ($b as $del) {
+		$changes[$del['id']]['del'][] = 2;
+	}
+	assertType('array<non-empty-array{add?: non-empty-list<1>, del?: non-empty-list<2>}>', $changes);
+};
diff --git a/tests/PHPStan/Analyser/nsrt/bug-12078.php b/tests/PHPStan/Analyser/nsrt/bug-12078.php
new file mode 100644
index 0000000000..4bf6fef7f5
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-12078.php
@@ -0,0 +1,44 @@
+<?php declare(strict_types = 1);
+
+namespace Bug12078;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @return array <string,string>
+ */
+function returnsData6M(): array
+{
+	return ["A"=>'data A',"B"=>'Data B'];
+}
+/**
+ * @return array <string,string>
+ */
+function returnsData3M(): array
+{
+	return ["A"=>'data A',"C"=>'Data C'];
+}
+
+function main(){
+	$arrDataByKey = [];
+
+	$arrData6M = returnsData6M();
+	if([] === $arrData6M){
+		echo "No data for 6M\n";
+	}else{
+		foreach($arrData6M as $key => $data){
+			$arrDataByKey[$key]['6M'][] = $data;
+		}
+	}
+
+	$arrData3M = returnsData3M();
+	if([] === $arrData3M){
+		echo "No data for 3M\n";
+	}else{
+		foreach($arrData3M as $key => $data){
+			$arrDataByKey[$key]['3M'][] = $data;
+		}
+	}
+
+	assertType('array<string, non-empty-array{6M?: non-empty-list<string>, 3M?: non-empty-list<string>}>', $arrDataByKey);
+}
diff --git a/tests/PHPStan/Analyser/nsrt/bug-6173.php b/tests/PHPStan/Analyser/nsrt/bug-6173.php
new file mode 100644
index 0000000000..89b16880f8
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-6173.php
@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace Bug6173;
+
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	/**
+	 * @param int[] $ids1
+	 * @param int[] $ids2
+	 */
+	public function sayHello(array $ids1, array $ids2): bool
+	{
+		$res = [];
+		foreach ($ids1 as $id) {
+			$res[$id]['foo'] = $id;
+		}
+
+		foreach ($ids2 as $id) {
+			$res[$id]['bar'] = $id;
+		}
+
+		assertType('array<int, non-empty-array{foo?: int, bar?: int}>', $res);
+
+		return true;
+	}
+}
diff --git a/tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php b/tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php
index 518fabc0b9..1f68f3000c 100644
--- a/tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php
+++ b/tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php
@@ -829,4 +829,10 @@ public function testArrayDimFetchAfterArraySearch(): void
 		]);
 	}
 
+	public function testBug11679(): void
+	{
+		$this->reportPossiblyNonexistentGeneralArrayOffset = true;
+		$this->analyse([__DIR__ . '/data/bug-11679.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Arrays/data/bug-11679.php b/tests/PHPStan/Rules/Arrays/data/bug-11679.php
new file mode 100644
index 0000000000..e038897bb2
--- /dev/null
+++ b/tests/PHPStan/Rules/Arrays/data/bug-11679.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Bug11679;
+
+class WorkingExample
+{
+	/** @var array{foo?: bool} */
+	private array $arr = [];
+
+	public function sayHello(): bool
+	{
+		if (!isset($this->arr['foo'])) {
+			$this->arr['foo'] = true;
+		}
+		return $this->arr['foo'];
+	}
+}
+
+class NonworkingExample
+{
+	/** @var array<int, array{foo?: bool}> */
+	private array $arr = [];
+
+	public function sayHello(int $index): bool
+	{
+		if (!isset($this->arr[$index]['foo'])) {
+			$this->arr[$index]['foo'] = true;
+		}
+		return $this->arr[$index]['foo'];
+	}
+}
diff --git a/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php b/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
index 5e57ee2994..fd498ae219 100644
--- a/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
+++ b/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
@@ -502,6 +502,11 @@ public function testBug6356b(): void
 				26,
 				"Offset 'age' (int) does not accept type int|string.",
 			],
+			[
+				'Property Bug6356b\HelloWorld2::$nestedDetails (array<array{name: string, age: int}>) does not accept non-empty-array<array{age: \'Eleventy-one\'|\'Five\'|\'Twelve\'|int, name: string}>.',
+				29,
+				'Offset \'age\' (int) does not accept type int|string.',
+			],
 		]);
 	}