Fix #30147 partially applied function crash.

Occurs when there are both bounds and also partially provided type
args. Attempt to still perform substitution analysis even during
partial application, so long as the partial application warning is
still provided.

Bug: 30147
Change-Id: I25a6dabe458494ee9fd6c53aeba75883c3143816
Reviewed-on: https://dart-review.googlesource.com/26040
Commit-Queue: Mike Fairhurst <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: MichaelRFairhurst

pkg/analyzer/lib/src/generated/error_verifier.dart

@@ -6246,9 +6246,14 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
           TypeParameterTypeImpl.getTypes(genericType.typeFormals);
       var typeArgs = typeArgumentList.map((t) => t.type).toList();
 
-      for (int i = 0, len = math.min(typeArgs.length, fnTypeParams.length);
-          i < len;
-          i++) {
+      // If the amount mismatches, clean up the lists to be substitutable. The
+      // mismatch in size is reported elsewhere, but we must successfully
+      // perform substitution to validate bounds on mismatched lists.
+      final providedLength = math.min(typeArgs.length, fnTypeParams.length);
+      fnTypeParams = fnTypeParams.sublist(0, providedLength);
+      typeArgs = typeArgs.sublist(0, providedLength);
+
+      for (int i = 0; i < providedLength; i++) {
         // Check the `extends` clause for the type parameter, if any.
         //
         // Also substitute to handle cases like this:

pkg/analyzer/test/generated/strong_mode_test.dart

@@ -3441,6 +3441,22 @@ void test<S>(T pf<T>(T e)) {
     expectIdentifierType('paramTearOff', "<T>(T) → T");
   }
 
+  test_genericMethod_partiallyAppliedErrorWithBound() async {
+    await resolveTestUnit(r'''
+void f<X extends List, Y>() => null;
+
+void test() {
+  f<int>();
+}
+''', noErrors: false);
+    assertErrors(testSource, [
+      // Make sure to catch both the missing parameter:
+      StaticTypeWarningCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_METHOD,
+      // And the incorrect parameter:
+      StaticTypeWarningCode.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS
+    ]);
+  }
+
   test_genericMethod_then() async {
     String code = r'''
 import 'dart:async';