Fix SliverList scrollOffsetCorrection 0 case (#62615)

packages/flutter/lib/src/rendering/sliver_list.dart

@@ -169,22 +169,28 @@ class RenderSliverList extends RenderSliverMultiBoxAdaptor {
     // If the scroll offset is at zero, we should make sure we are
     // actually at the beginning of the list.
     if (scrollOffset < precisionErrorTolerance) {
-      if (indexOf(firstChild) > 0) {
+      // We iterate from the firstChild in case the leading child has a 0 paint
+      // extent.
+      while (indexOf(firstChild) > 0) {
         final double earliestScrollOffset = childScrollOffset(firstChild);
         // We correct one child at a time. If there are more children before
         // the earliestUsefulChild, we will correct it once the scroll offset
-        // reach zero again.
+        // reaches zero again.
         earliestUsefulChild = insertAndLayoutLeadingChild(childConstraints, parentUsesSize: true);
         assert(earliestUsefulChild != null);
         final double firstChildScrollOffset = earliestScrollOffset - paintExtentOf(firstChild);
+        final SliverMultiBoxAdaptorParentData childParentData = firstChild.parentData as SliverMultiBoxAdaptorParentData;
+        childParentData.layoutOffset = 0.0;
+        // We only need to correct if the leading child actually has a
+        // paint extent.
+        if (firstChildScrollOffset < -precisionErrorTolerance) {
           geometry = SliverGeometry(
             scrollOffsetCorrection: -firstChildScrollOffset,
           );
-        final SliverMultiBoxAdaptorParentData childParentData = firstChild.parentData as SliverMultiBoxAdaptorParentData;
-        childParentData.layoutOffset = 0.0;
           return;
         }
       }
+    }
 
     // At this point, earliestUsefulChild is the first child, and is a child
     // whose scrollOffset is at or before the scrollOffset, and

packages/flutter/test/widgets/slivers_test.dart

@@ -814,6 +814,31 @@ void main() {
       expect(events, equals(<String>['tap']));
     });
   });
+
+  testWidgets('SliverList handles 0 scrollOffsetCorrection', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/62198
+    await tester.pumpWidget(MaterialApp(
+      home: Scaffold(
+        body: CustomScrollView(
+          physics: const BouncingScrollPhysics(parent: AlwaysScrollableScrollPhysics()),
+          slivers: <Widget>[
+            SliverList(
+              delegate: SliverChildListDelegate(
+                const <Widget>[
+                  SizedBox.shrink(),
+                  Text('index 1'),
+                  Text('index 2'),
+                ]
+              ),
+            ),
+          ],
+        )
+      ),
+    ));
+    await tester.fling(find.byType(Scrollable), const Offset(0.0, -500.0), 10000.0);
+    await tester.pumpAndSettle();
+    expect(tester.takeException(), isNull);
+  });
 }
 
 bool isRight(Offset a, Offset b) => b.dx > a.dx;