internal/syscall/windows/registry: blacklist certain registry keys in TestWalkFullRegistry

It turns out that Windows has "legitimate" keys that have bogus type
values or bogus lengths that don't correspond with their type. On up to
date Windows 10 systems, this test always fails for this reason. These
keys exist because of bugs in Microsoft's code. This commit works around
the problem by simply blacklisting known instances. It also expands the
error message a bit so that we can make adjustments should the problem
ever happen again, and reformats the messages so that it makes copy and
pasting into the blacklist easier.

Updates #35084

Change-Id: I50322828c0eb0ccecbb62d6bf4f9c726fa0b3c27
Reviewed-on: https://go-review.googlesource.com/c/go/+/202897
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/internal/syscall/windows/registry/registry_test.go

@@ -522,60 +522,75 @@ func TestValues(t *testing.T) {
 	deleteValues(t, k)
 }
 
+// These are known to be broken due to Windows bugs. See https://golang.org/issue/35084
+var blackListedKeys = map[string]bool{
+	`HKCU\Software\Microsoft\Windows\CurrentVersion\Group Policy\`:             true,
+	`HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\`:             true,
+	`HKLM\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Group Policy\`: true,
+	`HKLM\SYSTEM\ControlSet001\`:                                               true,
+	`HKLM\SYSTEM\ControlSet002\`:                                               true,
+	`HKLM\SYSTEM\CurrentControlSet\`:                                           true,
+	`HKLM\SYSTEM\DriverDatabase\`:                                              true,
+	`HKU\`:                                                                     true, // Rather unfortunate, but SIDs are hard to predict.
+}
+
 func walkKey(t *testing.T, k registry.Key, kname string) {
+	if blackListedKeys[kname+`\`] {
+		return
+	}
 	names, err := k.ReadValueNames(-1)
 	if err != nil {
-		t.Fatalf("reading value names of %s failed: %v", kname, err)
+		t.Fatalf("reading value names of %#q failed: %v", kname+`\`, err)
 	}
 	for _, name := range names {
+		if blackListedKeys[kname+`\`+name] {
+			continue
+		}
 		_, valtype, err := k.GetValue(name, nil)
 		if err != nil {
-			t.Fatalf("reading value type of %s of %s failed: %v", name, kname, err)
+			t.Fatalf("reading value type of %#q in %#q failed: %v", name, kname+`\`, err)
 		}
 		switch valtype {
 		case registry.NONE:
 		case registry.SZ:
 			_, _, err := k.GetStringValue(name)
 			if err != nil {
-				t.Error(err)
+				t.Errorf("getting %#q string value in %#q failed: %v", name, kname+`\`, err)
 			}
 		case registry.EXPAND_SZ:
 			s, _, err := k.GetStringValue(name)
 			if err != nil {
-				t.Error(err)
+				t.Errorf("getting %#q expand string value in %#q failed: %v", name, kname+`\`, err)
 			}
 			_, err = registry.ExpandString(s)
 			if err != nil {
-				t.Error(err)
+				t.Errorf("expanding %#q value in %#q failed: %v", name, kname+`\`, err)
 			}
 		case registry.DWORD, registry.QWORD:
 			_, _, err := k.GetIntegerValue(name)
 			if err != nil {
-				// Sometimes legitimate keys have the wrong sizes, which don't correspond with
-				// their required size, due to Windows bugs.
-				t.Logf("warning: GetIntegerValue for type %d of %s of %s failed: %v", valtype, name, kname, err)
+				t.Errorf("getting %#q integer value in %#q failed: %v", name, kname+`\`, err)
 			}
 		case registry.BINARY:
 			_, _, err := k.GetBinaryValue(name)
 			if err != nil {
-				t.Error(err)
+				t.Errorf("getting %#q binary value in %#q failed: %v", name, kname+`\`, err)
 			}
 		case registry.MULTI_SZ:
 			_, _, err := k.GetStringsValue(name)
 			if err != nil {
-				t.Error(err)
+				t.Errorf("getting %#q strings value in %#q failed: %v", name, kname+`\`, err)
 			}
 		case registry.FULL_RESOURCE_DESCRIPTOR, registry.RESOURCE_LIST, registry.RESOURCE_REQUIREMENTS_LIST:
 			// TODO: not implemented
 		default:
-			// Sometimes legitimate keys have the wrong value type, due to Windows bugs.
-			t.Logf("warning: value type %d of %s of %s failed: %v", valtype, name, kname, err)
+			t.Fatalf("%#q in %#q has unknown value type %d", name, kname+`\`, valtype)
 		}
 	}
 
 	names, err = k.ReadSubKeyNames(-1)
 	if err != nil {
-		t.Fatalf("reading sub-keys of %s failed: %v", kname, err)
+		t.Fatalf("reading sub-keys of %#q failed: %v", kname+`\`, err)
 	}
 	for _, name := range names {
 		func() {
@@ -585,7 +600,7 @@ func walkKey(t *testing.T, k registry.Key, kname string) {
 					// ignore error, if we are not allowed to access this key
 					return
 				}
-				t.Fatalf("opening sub-keys %s of %s failed: %v", name, kname, err)
+				t.Fatalf("opening sub-keys %#q in %#q failed: %v", name, kname+`\`, err)
 			}
 			defer subk.Close()
 
@@ -598,11 +613,11 @@ func TestWalkFullRegistry(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping long running test in short mode")
 	}
-	walkKey(t, registry.CLASSES_ROOT, "CLASSES_ROOT")
-	walkKey(t, registry.CURRENT_USER, "CURRENT_USER")
-	walkKey(t, registry.LOCAL_MACHINE, "LOCAL_MACHINE")
-	walkKey(t, registry.USERS, "USERS")
-	walkKey(t, registry.CURRENT_CONFIG, "CURRENT_CONFIG")
+	walkKey(t, registry.CLASSES_ROOT, "HKCR")
+	walkKey(t, registry.CURRENT_USER, "HKCU")
+	walkKey(t, registry.LOCAL_MACHINE, "HKLM")
+	walkKey(t, registry.USERS, "HKU")
+	walkKey(t, registry.CURRENT_CONFIG, "HKCC")
 }
 
 func TestExpandString(t *testing.T) {