Revert "Fonts: Allowing PushFont()/PopFont() to be called outside the imgui frame scope. (#3621)"

This reverts commit 61d4bf95dc5345c77b97b279011fce2c46efcaa8.

docs/CHANGELOG.txt

@@ -58,7 +58,6 @@ Other changes:
   yourself based on your own logic. (#8223)
 - Nav: Fixed an issue where Alt key would clear current active item on
   windows with the ImGuiWindowFlags_NoNavInputs flag. (#8231)
-- Fonts: Allowing PushFont()/PopFont() to be called outside the imgui frame scope. (#3621)
 - Debug Tools: Debug Log: hovering 0xXXXXXXXX values in log is allowed even
   if a popup is blocking mouse access to the debug log window. (#5855)
 - Backends: Vulkan: Fixed setting VkSwapchainCreateInfoKHR::preTransform for

imgui.cpp

@@ -8018,8 +8018,7 @@ void ImGui::PushFont(ImFont* font)
         font = GetDefaultFont();
     g.FontStack.push_back(font);
     SetCurrentFont(font);
-    if (ImGuiWindow* window = g.CurrentWindow)
-        window->DrawList->_SetTextureID(font->ContainerAtlas->TexID);
+    g.CurrentWindow->DrawList->_SetTextureID(font->ContainerAtlas->TexID);
 }
 
 void  ImGui::PopFont()
@@ -8033,8 +8032,7 @@ void  ImGui::PopFont()
     g.FontStack.pop_back();
     ImFont* font = g.FontStack.Size == 0 ? GetDefaultFont() : g.FontStack.back();
     SetCurrentFont(font);
-    if (ImGuiWindow* window = g.CurrentWindow)
-        window->DrawList->_SetTextureID(font->ContainerAtlas->TexID);
+    g.CurrentWindow->DrawList->_SetTextureID(font->ContainerAtlas->TexID);
 }
 
 void ImGui::PushItemFlag(ImGuiItemFlags option, bool enabled)