diff --git a/src/Psalm/CallMap.php b/src/Psalm/CallMap.php
index c0f712253..9b169778f 100644
--- a/src/Psalm/CallMap.php
+++ b/src/Psalm/CallMap.php
@@ -7606,7 +7606,7 @@ return [
 'ReflectionClass::getModifiers' => ['int'],
 'ReflectionClass::getNamespaceName' => ['string'],
 'ReflectionClass::getName' => ['string'],
-'ReflectionClass::getParentClass' => ['ReflectionClass'],
+'ReflectionClass::getParentClass' => ['?ReflectionClass'],
 'ReflectionClass::getProperties' => ['array', 'filter='=>'int'],
 'ReflectionClass::getProperty' => ['ReflectionProperty', 'name'=>'string'],
 'ReflectionClass::getShortName' => ['string'],
diff --git a/src/Psalm/Checker/ClassLikeChecker.php b/src/Psalm/Checker/ClassLikeChecker.php
index 251f517df..a7cb5fd26 100644
--- a/src/Psalm/Checker/ClassLikeChecker.php
+++ b/src/Psalm/Checker/ClassLikeChecker.php
@@ -1562,12 +1562,12 @@ abstract class ClassLikeChecker extends SourceChecker implements StatementsSourc
 
         $class_storage = $project_checker->classlike_storage_provider->get($declaring_property_class);
 
-        $storage = $class_storage->properties[$property_name];
-
-        if (!$storage) {
+        if (!isset($class_storage->properties[$property_name])) {
             throw new \UnexpectedValueException('$storage should not be null for ' . $property_id);
         }
 
+        $storage = $class_storage->properties[$property_name];
+
         switch ($storage->visibility) {
             case self::VISIBILITY_PUBLIC:
                 return null;
diff --git a/src/Psalm/Checker/FunctionLikeChecker.php b/src/Psalm/Checker/FunctionLikeChecker.php
index e6fbfb898..0dbcf342b 100644
--- a/src/Psalm/Checker/FunctionLikeChecker.php
+++ b/src/Psalm/Checker/FunctionLikeChecker.php
@@ -934,7 +934,7 @@ abstract class FunctionLikeChecker extends SourceChecker implements StatementsSo
         }
 
         if (!$return_type) {
-            if ($inferred_return_type && !$inferred_return_type->isMixed()) {
+            if (!$inferred_return_type->isMixed()) {
                 $this->addDocblockReturnType($project_checker, $inferred_return_type);
             }
 
@@ -983,7 +983,7 @@ abstract class FunctionLikeChecker extends SourceChecker implements StatementsSo
             );
         }
 
-        if ($inferred_return_type && !$declared_return_type->isMixed()) {
+        if (!$declared_return_type->isMixed()) {
             if ($inferred_return_type->isVoid() && $declared_return_type->isVoid()) {
                 return null;
             }
diff --git a/src/Psalm/Checker/MethodChecker.php b/src/Psalm/Checker/MethodChecker.php
index fdc8e0e35..8bf9959d4 100644
--- a/src/Psalm/Checker/MethodChecker.php
+++ b/src/Psalm/Checker/MethodChecker.php
@@ -39,9 +39,7 @@ class MethodChecker extends FunctionLikeChecker
         if ($method_id = self::getDeclaringMethodId($project_checker, $method_id)) {
             $storage = self::getStorage($project_checker, $method_id);
 
-            if ($storage) {
-                return $storage->params;
-            }
+            return $storage->params;
         }
 
         throw new \UnexpectedValueException('Cannot get method params for ' . $method_id);
@@ -84,10 +82,6 @@ class MethodChecker extends FunctionLikeChecker
 
         $storage = self::getStorage($project_checker, $method_id);
 
-        if (!$storage) {
-            throw new \UnexpectedValueException('$storage should not be null for ' . $method_id);
-        }
-
         if ($storage->return_type) {
             return $storage->return_type;
         }
@@ -97,7 +91,7 @@ class MethodChecker extends FunctionLikeChecker
         foreach ($class_storage->overridden_method_ids[$method_name] as $overridden_method_id) {
             $overridden_storage = self::getStorage($project_checker, $overridden_method_id);
 
-            if ($overridden_storage && $overridden_storage->return_type) {
+            if ($overridden_storage->return_type) {
                 if ($overridden_storage->return_type->isNull()) {
                     return Type::getVoid();
                 }
@@ -128,17 +122,13 @@ class MethodChecker extends FunctionLikeChecker
 
         $storage = self::getStorage($project_checker, $method_id);
 
-        if (!$storage) {
-            throw new \UnexpectedValueException('$storage should not be null for ' . $method_id);
-        }
-
         if (!$storage->return_type_location) {
             $overridden_method_ids = self::getOverriddenMethodIds($project_checker, $method_id);
 
             foreach ($overridden_method_ids as $overridden_method_id) {
                 $overridden_storage = self::getStorage($project_checker, $overridden_method_id);
 
-                if ($overridden_storage && $overridden_storage->return_type_location) {
+                if ($overridden_storage->return_type_location) {
                     $defined_location = $overridden_storage->return_type_location;
                     break;
                 }
@@ -262,10 +252,6 @@ class MethodChecker extends FunctionLikeChecker
 
         $storage = self::getStorage($project_checker, $method_id);
 
-        if (!$storage) {
-            throw new \UnexpectedValueException('$storage should not be null');
-        }
-
         if (!$storage->is_static) {
             if ($self_call) {
                 if (IssueBuffer::accepts(
@@ -496,10 +482,6 @@ class MethodChecker extends FunctionLikeChecker
 
         $storage = self::getStorage($project_checker, $declaring_method_id);
 
-        if (!$storage) {
-            throw new \UnexpectedValueException('$storage should not be null for ' . $declaring_method_id);
-        }
-
         switch ($storage->visibility) {
             case ClassLikeChecker::VISIBILITY_PUBLIC:
                 return true;
@@ -583,10 +565,6 @@ class MethodChecker extends FunctionLikeChecker
 
         $storage = self::getStorage($project_checker, $declaring_method_id);
 
-        if (!$storage) {
-            throw new \UnexpectedValueException('$storage should not be null for ' . $declaring_method_id);
-        }
-
         switch ($storage->visibility) {
             case ClassLikeChecker::VISIBILITY_PUBLIC:
                 return null;
@@ -772,10 +750,6 @@ class MethodChecker extends FunctionLikeChecker
 
         $storage = self::getStorage($project_checker, $method_id);
 
-        if (!$storage) {
-            throw new \UnexpectedValueException('$storage should not be null for ' . $method_id);
-        }
-
         list($fq_class_name) = explode('::', $method_id);
 
         return $fq_class_name . '::' . $storage->cased_name;
diff --git a/src/Psalm/Checker/ProjectChecker.php b/src/Psalm/Checker/ProjectChecker.php
index 092790f7f..444889ae9 100644
--- a/src/Psalm/Checker/ProjectChecker.php
+++ b/src/Psalm/Checker/ProjectChecker.php
@@ -441,7 +441,6 @@ class ProjectChecker
 
     /**
      * @return void
-     * @psalm-suppress ParadoxicalCondition
      */
     public function scanFiles()
     {
diff --git a/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php b/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php
index b17bdf039..7bfb42b0b 100644
--- a/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php
@@ -1146,6 +1146,7 @@ class AssignmentChecker
         // First go from the root element up, and go as far as we can to figure out what
         // array types there are
         while ($child_stmts) {
+            /** @var PhpParser\Node\Expr\ArrayDimFetch */
             $child_stmt = array_shift($child_stmts);
 
             if (count($child_stmts)) {
diff --git a/src/Psalm/Checker/Statements/Expression/CallChecker.php b/src/Psalm/Checker/Statements/Expression/CallChecker.php
index 8d9640f82..b4c383939 100644
--- a/src/Psalm/Checker/Statements/Expression/CallChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/CallChecker.php
@@ -171,15 +171,13 @@ class CallChecker
                     if ($var_type_part instanceof Type\Atomic\Fn) {
                         $function_params = $var_type_part->params;
 
-                        if ($var_type_part->return_type) {
-                            if (isset($stmt->inferredType)) {
-                                $stmt->inferredType = Type::combineUnionTypes(
-                                    $stmt->inferredType,
-                                    $var_type_part->return_type
-                                );
-                            } else {
-                                $stmt->inferredType = $var_type_part->return_type;
-                            }
+                        if (isset($stmt->inferredType)) {
+                            $stmt->inferredType = Type::combineUnionTypes(
+                                $stmt->inferredType,
+                                $var_type_part->return_type
+                            );
+                        } else {
+                            $stmt->inferredType = $var_type_part->return_type;
                         }
 
                         $function_exists = true;
@@ -2179,7 +2177,7 @@ class CallChecker
             $array_arg_types[] = $array_arg_type;
         }
 
-        /** @var PhpParser\Node\Arg */
+        /** @var ?PhpParser\Node\Arg */
         $closure_arg = isset($args[$closure_index]) ? $args[$closure_index] : null;
 
         /** @var Type\Union|null */
@@ -2191,7 +2189,7 @@ class CallChecker
 
         $project_checker = $file_checker->project_checker;
 
-        if ($closure_arg_type) {
+        if ($closure_arg && $closure_arg_type) {
             $min_closure_param_count = $max_closure_param_count = count($array_arg_types);
 
             if ($method_id === 'array_filter') {
diff --git a/src/Psalm/Checker/Statements/Expression/FetchChecker.php b/src/Psalm/Checker/Statements/Expression/FetchChecker.php
index 2ae6cb4d5..2c84f0a56 100644
--- a/src/Psalm/Checker/Statements/Expression/FetchChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/FetchChecker.php
@@ -850,7 +850,8 @@ class FetchChecker
                         if (!TypeChecker::isContainedBy(
                             $project_checker,
                             $offset_type,
-                            $type->type_params[0]
+                            $type->type_params[0],
+                            $offset_type->ignore_nullable_issues
                         )) {
                             $invalid_offset_types[] = (string)$type->type_params[0];
                         } else {
@@ -939,7 +940,7 @@ class FetchChecker
                                     $type->properties[$int_key_value]
                                 );
                             }
-                        } elseif ($string_key_value && $in_assignment && $string_key_value) {
+                        } elseif ($string_key_value && $in_assignment) {
                             $type->properties[$string_key_value] = new Type\Union([new TEmpty]);
 
                             if (!$array_access_type) {
@@ -968,7 +969,8 @@ class FetchChecker
                     } elseif (TypeChecker::isContainedBy(
                         $project_checker,
                         $offset_type,
-                        Type::getString()
+                        Type::getString(),
+                        $offset_type->ignore_nullable_issues
                     )) {
                         if ($replacement_type) {
                             $generic_params = Type::combineUnionTypes(
diff --git a/src/Psalm/Checker/Statements/ExpressionChecker.php b/src/Psalm/Checker/Statements/ExpressionChecker.php
index d958d61a0..c4d19b8aa 100644
--- a/src/Psalm/Checker/Statements/ExpressionChecker.php
+++ b/src/Psalm/Checker/Statements/ExpressionChecker.php
@@ -2085,23 +2085,21 @@ class ExpressionChecker
             if (isset($stmt->if->inferredType)) {
                 $lhs_type = $stmt->if->inferredType;
             }
-        } elseif ($stmt->cond) {
-            if (isset($stmt->cond->inferredType)) {
-                $if_return_type_reconciled = TypeChecker::reconcileTypes(
-                    '!falsy',
-                    $stmt->cond->inferredType,
-                    '',
-                    $statements_checker,
-                    new CodeLocation($statements_checker->getSource(), $stmt),
-                    $statements_checker->getSuppressedIssues()
-                );
+        } elseif (isset($stmt->cond->inferredType)) {
+            $if_return_type_reconciled = TypeChecker::reconcileTypes(
+                '!falsy',
+                $stmt->cond->inferredType,
+                '',
+                $statements_checker,
+                new CodeLocation($statements_checker->getSource(), $stmt),
+                $statements_checker->getSuppressedIssues()
+            );
 
-                if ($if_return_type_reconciled === false) {
-                    return false;
-                }
-
-                $lhs_type = $if_return_type_reconciled;
+            if ($if_return_type_reconciled === false) {
+                return false;
             }
+
+            $lhs_type = $if_return_type_reconciled;
         }
 
         if (!$lhs_type || !isset($stmt->else->inferredType)) {
diff --git a/src/Psalm/PropertyMap.php b/src/Psalm/PropertyMap.php
index 565a225a8..b4d86aeba 100644
--- a/src/Psalm/PropertyMap.php
+++ b/src/Psalm/PropertyMap.php
@@ -409,6 +409,12 @@ return [
     'phpparser\\node\\expr\\new_' => [
         'args' => 'array<int, PhpParser\Node\Arg>',
     ],
+    'phpparser\node\expr\array_' => [
+        'items' => 'array<int, phpparser\node\expr\arrayitem>',
+    ],
+    'phpparser\node\expr\list_' => [
+        'items' => 'array<int, phpparser\node\expr\arrayitem|null>',
+    ],
     'phpparser\\node\\expr\\methodcall' => [
         'args' => 'array<int, PhpParser\Node\Arg>',
     ],
diff --git a/src/Psalm/Stubs/CoreGenericFunctions.php b/src/Psalm/Stubs/CoreGenericFunctions.php
index c53cf63c7..62ac543b0 100644
--- a/src/Psalm/Stubs/CoreGenericFunctions.php
+++ b/src/Psalm/Stubs/CoreGenericFunctions.php
@@ -88,7 +88,8 @@ function array_diff_key(array $arr, array $arr2, array $arr3 = null, array $arr4
  * @template TValue
  *
  * @param array<TKey, TValue> $arr
- * @return TValue
+ * @return ?TValue
+ * @psalm-ignore-nullable-return
  */
 function array_shift(array &$arr) {}
 
@@ -97,7 +98,8 @@ function array_shift(array &$arr) {}
  * @template TValue
  *
  * @param array<TKey, TValue> $arr
- * @return TValue
+ * @return ?TValue
+ * @psalm-ignore-nullable-return
  */
 function array_pop(array &$arr) {}
 
diff --git a/tests/ReturnTypeTest.php b/tests/ReturnTypeTest.php
index 1751950e1..ff76e2dfd 100644
--- a/tests/ReturnTypeTest.php
+++ b/tests/ReturnTypeTest.php
@@ -518,8 +518,8 @@ class ReturnTypeTest extends TestCase
             ],
             'mixedInferredReturnType' => [
                 '<?php
-                    function fooFoo() : string {
-                        return array_pop([]);
+                    function fooFoo(array $arr) : string {
+                        return array_pop($arr);
                     }',
                 'error_message' => 'MixedInferredReturnType',
             ],