From a17ef11404442924b9886ccdecc0732f5fc00dd2 Mon Sep 17 00:00:00 2001
From: Timothy Nikkel <tnikkel@gmail.com>
Date: Wed, 24 Feb 2021 09:56:16 +0000
Subject: [PATCH] Bug 1690845. Don't ask Windows for the icon of an empty file
 extension because it returns the c: drive icon, which is not what we want.
 r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D105736
---
 image/decoders/icon/win/nsIconChannel.cpp                  | 6 ++++++
 image/test/reftest/generic/moz-icon-blank-1-almostref.html | 2 ++
 image/test/reftest/generic/moz-icon-blank-1-antiref.html   | 2 ++
 image/test/reftest/generic/moz-icon-blank-1-antiref2.html  | 2 ++
 image/test/reftest/generic/moz-icon-blank-1-ref.html       | 2 ++
 image/test/reftest/generic/moz-icon-blank-1.html           | 2 ++
 image/test/reftest/generic/reftest.list                    | 4 ++++
 7 files changed, 20 insertions(+)
 create mode 100644 image/test/reftest/generic/moz-icon-blank-1-almostref.html
 create mode 100644 image/test/reftest/generic/moz-icon-blank-1-antiref.html
 create mode 100644 image/test/reftest/generic/moz-icon-blank-1-antiref2.html
 create mode 100644 image/test/reftest/generic/moz-icon-blank-1-ref.html
 create mode 100644 image/test/reftest/generic/moz-icon-blank-1.html

diff --git a/image/decoders/icon/win/nsIconChannel.cpp b/image/decoders/icon/win/nsIconChannel.cpp
index 28d2ccc87374..3eaf9561f56f 100644
--- a/image/decoders/icon/win/nsIconChannel.cpp
+++ b/image/decoders/icon/win/nsIconChannel.cpp
@@ -503,6 +503,12 @@ nsresult nsIconChannel::GetHIconFromFile(bool aNonBlocking, HICON* hIcon) {
     filePath = u"."_ns + NS_ConvertUTF8toUTF16(defFileExt);
   }
 
+  if (!localFile && !fileExists &&
+      ((filePath.Length() == 1 && filePath.Last() == '.') ||
+       filePath.Length() == 0)) {
+    filePath = u".MozBogusExtensionMoz"_ns;
+  }
+
   if (aNonBlocking) {
     RefPtr<nsIEventTarget> target = DecodePool::Singleton()->GetIOEventTarget();
     RefPtr<IconAsyncOpenTask> task = new IconAsyncOpenTask(
diff --git a/image/test/reftest/generic/moz-icon-blank-1-almostref.html b/image/test/reftest/generic/moz-icon-blank-1-almostref.html
new file mode 100644
index 000000000000..38d5e1ec86f8
--- /dev/null
+++ b/image/test/reftest/generic/moz-icon-blank-1-almostref.html
@@ -0,0 +1,2 @@
+<!-- this should draw an icon similar to a blank document but with writing on it -->
+<img src="moz-icon://.txt?size=16">
diff --git a/image/test/reftest/generic/moz-icon-blank-1-antiref.html b/image/test/reftest/generic/moz-icon-blank-1-antiref.html
new file mode 100644
index 000000000000..2631ff40180c
--- /dev/null
+++ b/image/test/reftest/generic/moz-icon-blank-1-antiref.html
@@ -0,0 +1,2 @@
+<!-- this draws the icon for current directory on the c: drive on windows -->
+<img src="moz-icon:file:///C:/?size=16">
diff --git a/image/test/reftest/generic/moz-icon-blank-1-antiref2.html b/image/test/reftest/generic/moz-icon-blank-1-antiref2.html
new file mode 100644
index 000000000000..8553c81be0eb
--- /dev/null
+++ b/image/test/reftest/generic/moz-icon-blank-1-antiref2.html
@@ -0,0 +1,2 @@
+<!-- this draws the icon for the c: drive on windows -->
+<img src="moz-icon:file:///C://?size=16">
diff --git a/image/test/reftest/generic/moz-icon-blank-1-ref.html b/image/test/reftest/generic/moz-icon-blank-1-ref.html
new file mode 100644
index 000000000000..086d5af837e1
--- /dev/null
+++ b/image/test/reftest/generic/moz-icon-blank-1-ref.html
@@ -0,0 +1,2 @@
+<!-- this should draw a blank document icon -->
+<img src="moz-icon://bogus-unrecognized-icon.bogusunknown845?size=16">
diff --git a/image/test/reftest/generic/moz-icon-blank-1.html b/image/test/reftest/generic/moz-icon-blank-1.html
new file mode 100644
index 000000000000..2b52c96297b2
--- /dev/null
+++ b/image/test/reftest/generic/moz-icon-blank-1.html
@@ -0,0 +1,2 @@
+<!-- this should draw a blank document icon -->
+<img src="moz-icon://test?size=16&contentType=application/octet-stream">
diff --git a/image/test/reftest/generic/reftest.list b/image/test/reftest/generic/reftest.list
index bfc59b07c414..77d9c800635a 100644
--- a/image/test/reftest/generic/reftest.list
+++ b/image/test/reftest/generic/reftest.list
@@ -1,2 +1,6 @@
 HTTP == accept-image-catchall.html accept-image-catchall-ref.html
 skip-if(Android) != moz-icon-1.html about:blank
+== moz-icon-blank-1.html moz-icon-blank-1-ref.html
+skip-if(Android) != moz-icon-blank-1-ref.html moz-icon-blank-1-antiref.html
+skip-if(Android) != moz-icon-blank-1-ref.html moz-icon-blank-1-antiref2.html
+fuzzy-if(OSX,44,335) fuzzy-if(winWidget,64-78,45-68) == moz-icon-blank-1-almostref.html moz-icon-blank-1-ref.html