WebShare: Allow downloaded web pages to be shared

When a web page is downloaded in Android, and then shared using WebShare,
the "file name" reported to WebShare starts with "https://".

This patch allows such files to be shared.

Bug: 965461
Change-Id: If1922c81ade874bb7b8be06d88361e10b2db248b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1624525Reviewed-by: Raymes Khoury <raymes@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Eric Willigers <ericwilligers@chromium.org>
Auto-Submit: Eric Willigers <ericwilligers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666588}

chrome/android/java/src/org/chromium/chrome/browser/webshare/ShareServiceImpl.java

@@ -254,7 +254,8 @@ public class ShareServiceImpl implements ShareService {
     }
 
     static boolean isDangerousFilename(String name) {
-        return name.indexOf('/') != -1 || name.indexOf('\\') != -1 || name.indexOf('.') <= 0
+        // Reject filenames without a permitted extension.
+        return name.indexOf('.') <= 0
                 || !PERMITTED_EXTENSIONS.contains(FileUtils.getExtension(name));
     }
 

chrome/android/junit/src/org/chromium/chrome/browser/webshare/ShareServiceImplTest.java

@@ -21,15 +21,18 @@ import org.chromium.base.test.BaseRobolectricTestRunner;
 public class ShareServiceImplTest {
     @Test
     @SmallTest
-    public void testSlash() {
-        Assert.assertTrue(ShareServiceImpl.isDangerousFilename("foo/bar.txt"));
-        Assert.assertTrue(ShareServiceImpl.isDangerousFilename("foo\\bar.txt"));
-    }
-
-    @Test
-    @SmallTest
-    public void testPeriod() {
+    public void testExtensionFormatting() {
+        Assert.assertFalse(ShareServiceImpl.isDangerousFilename("foo/bar.txt"));
+        Assert.assertFalse(ShareServiceImpl.isDangerousFilename("foo\\bar\u03C0.txt"));
+        Assert.assertTrue(ShareServiceImpl.isDangerousFilename("foo\\bar.tx\u03C0t"));
+        Assert.assertFalse(ShareServiceImpl.isDangerousFilename("https://example.com/a/b.html"));
+        Assert.assertTrue(ShareServiceImpl.isDangerousFilename("foo/bar.txt/"));
+        Assert.assertTrue(ShareServiceImpl.isDangerousFilename("foobar.tx\\t"));
         Assert.assertTrue(ShareServiceImpl.isDangerousFilename("hello"));
+        Assert.assertTrue(ShareServiceImpl.isDangerousFilename("hellotxt"));
+        Assert.assertTrue(ShareServiceImpl.isDangerousFilename(".txt"));
+        Assert.assertFalse(ShareServiceImpl.isDangerousFilename("https://example.com/a/.txt"));
+        Assert.assertFalse(ShareServiceImpl.isDangerousFilename("/.txt"));
         Assert.assertTrue(ShareServiceImpl.isDangerousFilename(".."));
         Assert.assertTrue(ShareServiceImpl.isDangerousFilename(".hello.txt"));
     }