linkPreviewFetch: Increase maximum HTML we'll process to 1000*1024 bytes

Co-authored-by: Scott Nonnenberg <scott@signal.org>

ts/linkPreviews/linkPreviewFetch.ts

@@ -27,9 +27,9 @@ const MAX_CONTENT_TYPE_LENGTH_TO_PARSE = 100;
 
 // Though we'll accept HTML of any Content-Length (including no specified length), we
 //   will only load some of the HTML. So we might start loading a 99 gigabyte HTML page
-//   but only parse the first 500 kilobytes. However, if the Content-Length is less than
+//   but only parse the first 1000 kilobytes. However, if the Content-Length is less than
 //   this, we won't waste space.
-const MAX_HTML_BYTES_TO_LOAD = 500 * 1024;
+const MAX_HTML_BYTES_TO_LOAD = 1000 * 1024;
 
 // `<title>x` is 8 bytes. Nothing else (meta tags, etc) will even fit, so we can ignore
 //   it. This is mostly to protect us against empty response bodies.

ts/test-electron/linkPreviews/linkPreviewFetch_test.ts

@@ -843,7 +843,7 @@ describe('link preview fetching', () => {
       sinon.assert.notCalled(shouldNeverBeCalled);
     });
 
-    it('stops reading bodies after 500 kilobytes', async function test() {
+    it('stops reading bodies after 1000 kilobytes', async function test() {
       const shouldNeverBeCalled = sinon.stub();
 
       const fakeFetch = stub().resolves(
@@ -855,6 +855,9 @@ describe('link preview fetching', () => {
             const spaces = new Uint8Array(250 * 1024).fill(32);
             yield spaces;
             yield spaces;
+            yield spaces;
+            yield spaces;
+            yield spaces;
             shouldNeverBeCalled();
             yield new TextEncoder().encode(
               '<meta property="og:description" content="should be ignored">'