diff --git a/tests/integration/admin_config_test.go b/tests/integration/admin_config_test.go
index f077b3a84e..09e49874d6 100644
--- a/tests/integration/admin_config_test.go
+++ b/tests/integration/admin_config_test.go
@@ -21,29 +21,52 @@ func TestAdminConfig(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
 	session := loginUser(t, "user1")
-	req := NewRequest(t, "GET", "/-/admin/config")
-	resp := session.MakeRequest(t, req, http.StatusOK)
-	assert.True(t, test.IsNormalPageCompleted(resp.Body.String()))
+
+	t.Run("ConfigPage", func(t *testing.T) {
+		req := NewRequest(t, "GET", "/-/admin/config")
+		resp := session.MakeRequest(t, req, http.StatusOK)
+		assert.True(t, test.IsNormalPageCompleted(resp.Body.String()))
+	})
 
 	t.Run("OpenEditorWithApps", func(t *testing.T) {
 		cfg := setting.Config().Repository.OpenWithEditorApps
-		editorApps := cfg.Value(t.Context())
-		assert.Len(t, editorApps, 3)
-		assert.False(t, cfg.HasValue(t.Context()))
 
-		require.NoError(t, system.SetSettings(t.Context(), map[string]string{cfg.DynKey(): "[]"}))
-		config.GetDynGetter().InvalidateCache()
+		t.Run("Default", func(t *testing.T) {
+			editorApps := cfg.Value(t.Context())
+			assert.Len(t, editorApps, 3)
+			assert.False(t, cfg.HasValue(t.Context()))
+		})
 
-		editorApps = cfg.Value(t.Context())
-		assert.Len(t, editorApps, 3)
-		assert.False(t, cfg.HasValue(t.Context()))
+		t.Run("EmptyAsDefault", func(t *testing.T) {
+			require.NoError(t, system.SetSettings(t.Context(), map[string]string{cfg.DynKey(): "[]"}))
+			config.GetDynGetter().InvalidateCache()
 
-		require.NoError(t, system.SetSettings(t.Context(), map[string]string{cfg.DynKey(): "[{}]"}))
-		config.GetDynGetter().InvalidateCache()
+			editorApps := cfg.Value(t.Context())
+			assert.Len(t, editorApps, 3)
+			assert.False(t, cfg.HasValue(t.Context()))
+		})
 
-		editorApps = cfg.Value(t.Context())
-		assert.Len(t, editorApps, 1)
-		assert.True(t, cfg.HasValue(t.Context()))
+		t.Run("SingleItem", func(t *testing.T) {
+			require.NoError(t, system.SetSettings(t.Context(), map[string]string{cfg.DynKey(): "[{}]"}))
+			config.GetDynGetter().InvalidateCache()
+
+			editorApps := cfg.Value(t.Context())
+			assert.Len(t, editorApps, 1)
+			assert.True(t, cfg.HasValue(t.Context()))
+		})
+
+		t.Run("ManualSet", func(t *testing.T) {
+			req := NewRequestWithValues(t, "POST", "/-/admin/config", map[string]string{
+				"key":   "repository.open-with.editor-apps",
+				"value": `[{"DisplayName":"app-name","OpenURL":"my-app:?u={url}"}]`,
+			})
+			session.MakeRequest(t, req, http.StatusOK)
+			editorApps := cfg.Value(t.Context())
+			assert.Len(t, editorApps, 1)
+			assert.Equal(t, "app-name", editorApps[0].DisplayName)
+			assert.Equal(t, "my-app:?u={url}", editorApps[0].OpenURL)
+			assert.True(t, cfg.HasValue(t.Context()))
+		})
 	})
 
 	t.Run("InstanceWebBanner", func(t *testing.T) {
@@ -51,7 +74,7 @@ func TestAdminConfig(t *testing.T) {
 		assert.False(t, has)
 		assert.Equal(t, setting.WebBannerType{}, banner)
 
-		req = NewRequestWithValues(t, "POST", "/-/admin/config", map[string]string{
+		req := NewRequestWithValues(t, "POST", "/-/admin/config", map[string]string{
 			"key":   "instance.web_banner",
 			"value": `{"DisplayEnabled":true,"ContentMessage":"test-msg","StartTimeUnix":123,"EndTimeUnix":456}`,
 		})
diff --git a/web_src/js/features/admin/config.ts b/web_src/js/features/admin/config.ts
index 3abf28e4ea..41f4483a53 100644
--- a/web_src/js/features/admin/config.ts
+++ b/web_src/js/features/admin/config.ts
@@ -4,6 +4,7 @@ import {registerGlobalInitFunc} from '../../modules/observer.ts';
 import {queryElems} from '../../utils/dom.ts';
 import {errorMessage} from '../../modules/errors.ts';
 import {submitFormFetchAction} from '../common-fetch-action.ts';
+import {cutString} from '../../utils/string.ts';
 
 const {appSubUrl} = window.config;
 
@@ -158,7 +159,7 @@ export class ConfigFormValueMapper {
     const apps: Array<{DisplayName: string, OpenURL: string}> = [];
     const lines = cfgVal.split('\n');
     for (const line of lines) {
-      let [displayName, openUrl] = line.split('=', 2);
+      let [displayName, openUrl] = cutString(line, '=');
       displayName = displayName.trim();
       openUrl = openUrl?.trim() ?? '';
       if (!displayName || !openUrl) continue;
diff --git a/web_src/js/utils/string.test.ts b/web_src/js/utils/string.test.ts
new file mode 100644
index 0000000000..46b14097ac
--- /dev/null
+++ b/web_src/js/utils/string.test.ts
@@ -0,0 +1,13 @@
+import {cutString} from './string.ts';
+
+test('cutString', () => {
+  let [before, after, ok] = cutString('a = b = c', '=');
+  expect(before).toBe('a ');
+  expect(after).toBe(' b = c');
+  expect(ok).toBe(true);
+
+  [before, after, ok] = cutString(' a ', '=');
+  expect(before).toBe(' a ');
+  expect(after).toBe('');
+  expect(ok).toBe(false);
+});
diff --git a/web_src/js/utils/string.ts b/web_src/js/utils/string.ts
new file mode 100644
index 0000000000..48d4580dad
--- /dev/null
+++ b/web_src/js/utils/string.ts
@@ -0,0 +1,5 @@
+export function cutString(s: string, sep: string): [string, string, boolean] {
+  const index = s.indexOf(sep);
+  if (index === -1) return [s, '', false];
+  return [s.substring(0, index), s.substring(index + sep.length), true];
+}