fix(settings): preserve OpenAI form input on validation failure

app/controllers/settings/hostings_controller.rb

@@ -200,6 +200,12 @@ def update
 
     redirect_to settings_hosting_path, notice: t(".success")
   rescue Setting::ValidationError => error
+    # Preserve user-submitted OpenAI config so the form re-renders with their
+    # input intact (issue #1824). The form auto-submits on blur, so a partial
+    # entry (e.g. URI base before model) hits validation and would otherwise
+    # be wiped because the view reads from the unchanged Setting.* values.
+    @openai_uri_base_input = hosting_params[:openai_uri_base] if hosting_params.key?(:openai_uri_base)
+    @openai_model_input = hosting_params[:openai_model] if hosting_params.key?(:openai_model)
     flash.now[:alert] = error.message
     render :show, status: :unprocessable_entity
   end

app/views/settings/hostings/_openai_settings.html.erb

@@ -30,7 +30,7 @@
   <%= form.text_field :openai_uri_base,
                       label: t(".uri_base_label"),
                       placeholder: t(".uri_base_placeholder"),
-                      value: Setting.openai_uri_base,
+                      value: @openai_uri_base_input || Setting.openai_uri_base,
                       autocomplete: "off",
                       autocapitalize: "none",
                       spellcheck: "false",
@@ -41,7 +41,7 @@
   <%= form.text_field :openai_model,
                       label: t(".model_label"),
                       placeholder: t(".model_placeholder"),
-                      value: Setting.openai_model,
+                      value: @openai_model_input || Setting.openai_model,
                       autocomplete: "off",
                       autocapitalize: "none",
                       spellcheck: "false",

test/controllers/settings/hostings_controller_test.rb

@@ -95,6 +95,55 @@ class Settings::HostingsControllerTest < ActionDispatch::IntegrationTest
     end
   end
 
+  # Regression: issue #1824. The OpenAI form auto-submits on blur, so entering
+  # the URI base before the model fires a partial submit that fails validation.
+  # The re-rendered form must show the user's submitted URI base — not the
+  # still-blank saved value — so they can finish typing the model.
+  test "preserves submitted openai uri base in form when validation fails" do
+    with_self_hosting do
+      Setting.openai_uri_base = nil
+      Setting.openai_model = ""
+
+      patch settings_hosting_url, params: { setting: { openai_uri_base: "https://api.example.com/v1" } }
+
+      assert_response :unprocessable_entity
+      assert_select "input[name=?]", "setting[openai_uri_base]" do |inputs|
+        assert_equal "https://api.example.com/v1", inputs.first["value"]
+      end
+    end
+  ensure
+    Setting.openai_uri_base = nil
+    Setting.openai_model = nil
+  end
+
+  # PR #1862 review (jjmata): symmetric coverage for the model field. When the
+  # user changes the URI base and clears the model in the same auto-submit, the
+  # cross-field validation fails — the re-rendered model input must reflect the
+  # user's submitted (cleared) value, not silently revert to the saved model.
+  test "preserves submitted openai model in form when validation fails" do
+    with_self_hosting do
+      Setting.openai_uri_base = "https://saved.example.com/v1"
+      Setting.openai_model = "saved-model"
+
+      patch settings_hosting_url, params: { setting: {
+        openai_uri_base: "https://new.example.com/v1",
+        openai_model: ""
+      } }
+
+      assert_response :unprocessable_entity
+      assert_select "input[name=?]", "setting[openai_uri_base]" do |inputs|
+        assert_equal "https://new.example.com/v1", inputs.first["value"]
+      end
+      assert_select "input[name=?]", "setting[openai_model]" do |inputs|
+        assert_not_equal "saved-model", inputs.first["value"].to_s,
+          "model field must reflect the submitted (cleared) value, not the saved model"
+      end
+    end
+  ensure
+    Setting.openai_uri_base = nil
+    Setting.openai_model = nil
+  end
+
   test "can update openai model alone when self hosting is enabled" do
     with_self_hosting do
       patch settings_hosting_url, params: { setting: { openai_model: "gpt-4" } }