From e16f435326a3cbe22b14396ad484ac4dacf9c559 Mon Sep 17 00:00:00 2001
From: "blink-so[bot]" <211532188+blink-so[bot]@users.noreply.github.com>
Date: Thu, 7 Aug 2025 16:41:35 +0000
Subject: [PATCH] fix: preserve existing template fields in PATCH requests

Fixes issue where updating only specific fields (like default_ttl_ms)
would unintentionally clear other fields (like icon, display_name,
description) when they weren't provided in the PATCH request.

The fix preserves existing values for fields that are not explicitly
provided in the request, following the expected PATCH semantics.

Fixes #19036

Co-authored-by: matifali <10648092+matifali@users.noreply.github.com>
---
 coderd/templates.go      | 42 +++++++++++++++++++++++++++-------------
 coderd/templates_test.go |  9 ++++++---
 2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/coderd/templates.go b/coderd/templates.go
index f9c5d8271a1e6..799fcaef56b17 100644
--- a/coderd/templates.go
+++ b/coderd/templates.go
@@ -771,12 +771,34 @@ func (api *API) patchTemplateMeta(rw http.ResponseWriter, r *http.Request) {
 		classicTemplateFlow = *req.UseClassicParameterFlow
 	}
 
+	// Users should not be able to clear the template name in the UI
+	name := req.Name
+	if name == "" {
+		name = template.Name
+	}
+
+	// Preserve existing values for fields not provided in PATCH request
+	displayName := req.DisplayName
+	if displayName == "" {
+		displayName = template.DisplayName
+	}
+
+	description := req.Description
+	if description == "" {
+		description = template.Description
+	}
+
+	icon := req.Icon
+	if icon == "" {
+		icon = template.Icon
+	}
+
 	var updated database.Template
 	err = api.Database.InTx(func(tx database.Store) error {
-		if req.Name == template.Name &&
-			req.Description == template.Description &&
-			req.DisplayName == template.DisplayName &&
-			req.Icon == template.Icon &&
+		if name == template.Name &&
+			description == template.Description &&
+			displayName == template.DisplayName &&
+			icon == template.Icon &&
 			req.AllowUserAutostart == template.AllowUserAutostart &&
 			req.AllowUserAutostop == template.AllowUserAutostop &&
 			req.AllowUserCancelWorkspaceJobs == template.AllowUserCancelWorkspaceJobs &&
@@ -796,12 +818,6 @@ func (api *API) patchTemplateMeta(rw http.ResponseWriter, r *http.Request) {
 			return nil
 		}
 
-		// Users should not be able to clear the template name in the UI
-		name := req.Name
-		if name == "" {
-			name = template.Name
-		}
-
 		groupACL := template.GroupACL
 		if req.DisableEveryoneGroupAccess {
 			delete(groupACL, template.OrganizationID.String())
@@ -827,9 +843,9 @@ func (api *API) patchTemplateMeta(rw http.ResponseWriter, r *http.Request) {
 			ID:                           template.ID,
 			UpdatedAt:                    dbtime.Now(),
 			Name:                         name,
-			DisplayName:                  req.DisplayName,
-			Description:                  req.Description,
-			Icon:                         req.Icon,
+			DisplayName:                  displayName,
+			Description:                  description,
+			Icon:                         icon,
 			AllowUserCancelWorkspaceJobs: req.AllowUserCancelWorkspaceJobs,
 			GroupACL:                     groupACL,
 			MaxPortSharingLevel:          maxPortShareLevel,
diff --git a/coderd/templates_test.go b/coderd/templates_test.go
index 050ae77f8ca49..601c35215fa07 100644
--- a/coderd/templates_test.go
+++ b/coderd/templates_test.go
@@ -1377,7 +1377,7 @@ func TestPatchTemplateMeta(t *testing.T) {
 		assert.Equal(t, template.DefaultTTLMillis, updated.DefaultTTLMillis)
 	})
 
-	t.Run("RemoveIcon", func(t *testing.T) {
+	t.Run("PreserveIconWhenEmpty", func(t *testing.T) {
 		t.Parallel()
 
 		client := coderdtest.New(t, nil)
@@ -1386,15 +1386,18 @@ func TestPatchTemplateMeta(t *testing.T) {
 		template := coderdtest.CreateTemplate(t, client, user.OrganizationID, version.ID, func(ctr *codersdk.CreateTemplateRequest) {
 			ctr.Icon = "/icon/code.png"
 		})
+		// Test that when only updating other fields, the icon is preserved
 		req := codersdk.UpdateTemplateMeta{
-			Icon: "",
+			DefaultTTLMillis: 12 * time.Hour.Milliseconds(),
 		}
 
 		ctx := testutil.Context(t, testutil.WaitLong)
 
 		updated, err := client.UpdateTemplateMeta(ctx, template.ID, req)
 		require.NoError(t, err)
-		assert.Equal(t, updated.Icon, "")
+		// Icon should be preserved when not explicitly provided
+		assert.Equal(t, "/icon/code.png", updated.Icon)
+		assert.Equal(t, req.DefaultTTLMillis, updated.DefaultTTLMillis)
 	})
 
 	t.Run("AutostopRequirement", func(t *testing.T) {