Merge commit from fork

* SP-2025-03.1 always wrap icon&thumbnail URLs

if they're not HTTP URLs, the frontend won't be able to display them
anyway (`<img src="mailto:…">` or '<div stile="background-image:
url(nntp:…)">` aren't going to work!), so let's always run them through the
media proxy, which will fail harder (fetching a `javascript:` URL
won't do anything in the backend, might do something in the frontend)
and will always protect the client's address in cases like `gemini:`
where the browser could try to fetch

* SP-2025-03.2 use object binding for more styles

interpolating a random (remote-controlled!) string into a `style`
attribute is a bad idea; using VueJS object binding, we should get
proper quoting and therefore safe parse failures instead of CSS
injections / XSS

* SP-2025-03.3 slightly more robust "self" URL handling

parse URLs instead of treating them as strings; this is still not
perfect, but the `URL` class only handles full URLs, not relative
ones, so there's so way to ask it "give me a URL object that
represents this resource relative to this base URL"

notice that passing very weird URLs to `MkUrl` and `MkUrlPreview` will
break the frontend (in dev mode) because there's an untrapped `new
URL(…)` that may explode; production builds seem to safely ignore the
error, though

---------

Co-authored-by: dakkar <dakkar@thenautilus.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/packages/frontend/src/components/MkLink.vue b/packages/frontend/src/components/MkLink.vue
index 4bac2bcea4..4cbf289448 100644
--- a/packages/frontend/src/components/MkLink.vue
+++ b/packages/frontend/src/components/MkLink.vue
@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <template>
 <component
-	:is="self ? 'MkA' : 'a'" ref="el" style="word-break: break-all;" class="_link" :[attr]="self ? url.substring(local.length) : url" :rel="rel ?? 'nofollow noopener'" :target="target"
+	:is="self ? 'MkA' : 'a'" ref="el" style="word-break: break-all;" class="_link" :[attr]="maybeRelativeUrl" :rel="rel ?? 'nofollow noopener'" :target="target"
 	:behavior="props.navigationBehavior"
 	:title="url"
 >
@@ -21,6 +21,7 @@ import { useTooltip } from '@/use/use-tooltip.js';
 import * as os from '@/os.js';
 import { isEnabledUrlPreview } from '@/instance.js';
 import type { MkABehavior } from '@/components/global/MkA.vue';
+import { maybeMakeRelative } from '@@/js/url.js';
 
 const props = withDefaults(defineProps<{
 	url: string;
@@ -29,7 +30,8 @@ const props = withDefaults(defineProps<{
 }>(), {
 });
 
-const self = props.url.startsWith(local);
+const maybeRelativeUrl = maybeMakeRelative(props.url, local);
+const self = maybeRelativeUrl !== props.url;
 const attr = self ? 'to' : 'href';
 const target = self ? null : '_blank';