From 67bfdb970ba01d9bc2c69e52c62ffd58221f8d44 Mon Sep 17 00:00:00 2001
From: Marc Durdin <marc@durdin.net>
Date: Wed, 10 Mar 2021 10:34:55 +1100
Subject: [PATCH] fix(windows): Handle disabled profiles and invalid language
 ids

Fixes #4490.
Fixes #4435.

There are three parts to this:

1. Ensure that transient language profiles associated with a disabled
   keyboard are enumerated correctly
2. Stop trusting `LocaleNameToLCID` when it returns a transient language
   id, as it sometimes reports out-of-date values. We don't need to
   trust it in these cases anyway, because we have already collected the
   relevant transient language data from Win8Languages.
3. Finally, setting the profile GUID to `GUID_NULL` is simply tidyup,
   which does not have impact on the running code currently but makes
   state consistent.

I believe that part 2 fixes #4435 because the symptoms are identical.
But as I am unable to repro that particular issue on my machine thus
far, that is an assumption. Hopefully we can get a good test result from
@MakaraSok.
---
 .../keymankeyboardlanguageinstalled.pas       |  5 +--
 .../keymankeyboardlanguagesinstalled.pas      | 35 +++++++++++++++++++
 ...stem.Process.KPInstallKeyboardLanguage.pas | 11 ++++++
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguageinstalled.pas b/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguageinstalled.pas
index a195176f73..990386f0eb 100644
--- a/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguageinstalled.pas
+++ b/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguageinstalled.pas
@@ -134,9 +134,10 @@ begin
     try
       UninstallTip(FOwner.ID, Get_LangID, Get_ProfileGUID, False);
       if IsTransientLanguageID(Get_LangID) then
-        // TODO: this breaks re-enabling the keyboard because the reg entry is
-        // still referring to the old langid.
+      begin
         SetLangID(0);
+        FProfileGUID := GUID_NULL;
+      end;
     finally
       Free;
     end;
diff --git a/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguagesinstalled.pas b/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguagesinstalled.pas
index c9b6b75b9f..6f17470667 100644
--- a/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguagesinstalled.pas
+++ b/windows/src/engine/kmcomapi/com/keyboardlanguages/keymankeyboardlanguagesinstalled.pas
@@ -252,12 +252,47 @@ procedure TKeymanKeyboardLanguagesInstalled.DoRefresh;
     end;
   end;
 
+  // Adds custom transient profiles for a disabled
+  // keyboard which will not be found by enumerating
+  // LM values.
+  procedure RefreshDisabledProfiles;
+  var
+    reg: TRegistryErrorControlled;
+    RootPath: string;
+    ids: TStringList;
+    id: string;
+  begin
+    if FOwner.Loaded then
+      Exit;
+
+    ids := TStringList.Create;
+    reg := TRegistryErrorControlled.Create(KEY_READ);
+    try
+      RootPath := GetRegistryKeyboardActiveKey_CU(FOwner.ID) + '\' + SRegSubKey_KeyboardLanguages;
+      if reg.OpenKeyReadOnly(RootPath) then
+      begin
+        reg.GetValueNames(ids);
+        for id in ids do
+        begin
+          if not HasLanguage(id) then
+          begin
+            FLanguages.Add(TKeymanKeyboardLanguageInstalled.Create(Context, FOwner, id, 0, GUID_NULL, ''));
+          end;
+        end;
+      end;
+    finally
+      reg.Free;
+      ids.Free;
+    end;
+  end;
+
 begin
   KL.MethodEnter(Self, 'DoRefresh', []);
   try
     RefreshProfiles;
     RefreshTransientProfiles;
     RefreshSuggestedLanguages;
+    RefreshDisabledProfiles;
   finally
     KL.MethodExit(Self, 'DoRefresh');
   end;
diff --git a/windows/src/engine/kmcomapi/processes/keyboard/Keyman.System.Process.KPInstallKeyboardLanguage.pas b/windows/src/engine/kmcomapi/processes/keyboard/Keyman.System.Process.KPInstallKeyboardLanguage.pas
index ef4c1c2e64..d4c8208c2f 100644
--- a/windows/src/engine/kmcomapi/processes/keyboard/Keyman.System.Process.KPInstallKeyboardLanguage.pas
+++ b/windows/src/engine/kmcomapi/processes/keyboard/Keyman.System.Process.KPInstallKeyboardLanguage.pas
@@ -326,6 +326,17 @@ begin
     Exit(False);
   end;
 
+  if PRIMARYLANGID(LangID) = 0 then
+  begin
+    // LocaleNameToLCID can return a recently uninstalled transient LangID, but
+    // attempts to use that LangID result in an 'unknown locale' being
+    // installed, or a default locale being associated with the keyboard. Given
+    // an installed transient language will always be found in the
+    // Win8LanguageList, we should then assume that LocaleNameToLCID is lying to
+    // us and look for a new transient language id to be applied instead.
+    Exit(False);
+  end;
+
 
   case LangID of
     LOCALE_CUSTOM_DEFAULT,