Fix denoland/deno_std#409 handle multipart header in mime reader (denoland/deno_std#415)

Original: 92c26cc331

textproto/mod.ts

@@ -83,7 +83,8 @@ export class TextProtoReader {
 
     while (true) {
       let [kv, err] = await this.readLineSlice(); // readContinuedLineSlice
-      if (kv.byteLength == 0) {
+
+      if (kv.byteLength === 0) {
         return [m, err];
       }
 
@@ -140,10 +141,15 @@ export class TextProtoReader {
         // Go's len(typed nil) works fine, but not in JS
         return [new Uint8Array(0), err];
       }
+
       // Avoid the copy if the first call produced a full line.
       if (line == null && !more) {
+        if (this.skipSpace(l) === 0) {
+          return [new Uint8Array(0), null];
+        }
         return [l, null];
       }
+
       line = append(line, l);
       if (!more) {
         break;
@@ -151,4 +157,15 @@ export class TextProtoReader {
     }
     return [line, null];
   }
+
+  skipSpace(l: Uint8Array): number {
+    let n = 0;
+    for (let i = 0; i < l.length; i++) {
+      if (l[i] === charCode(" ") || l[i] === charCode("\t")) {
+        continue;
+      }
+      n++;
+    }
+    return n;
+  }
 }

textproto/reader_test.ts

@@ -165,3 +165,20 @@ test({
     assert(err instanceof ProtocolError);
   }
 });
+
+test({
+  name: "[textproto] #409 issue : multipart form boundary",
+  async fn(): Promise<void> {
+    const input = [
+      "Accept: */*\r\n",
+      'Content-Disposition: form-data; name="test"\r\n',
+      " \r\n",
+      "------WebKitFormBoundaryimeZ2Le9LjohiUiG--\r\n\n"
+    ];
+    const r = reader(input.join(""));
+    let [m, err] = await r.readMIMEHeader();
+    assertEquals(m.get("Accept"), "*/*");
+    assertEquals(m.get("Content-Disposition"), 'form-data; name="test"');
+    assert(!err);
+  }
+});