Vulkan: Fix a line loop edge case causing validation errors

Bug: angleproject:2563

Change-Id: I6e908fbd3e5725dc3f355f8b0561f2177b61dff6
Reviewed-on: https://chromium-review.googlesource.com/1075291
Commit-Queue: Luc Ferron <lucferron@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp b/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp
index 206cfaa..ce991d0 100644
--- a/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp
+++ b/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp
@@ -191,14 +191,16 @@
                     BufferVk *bufferVk                 = vk::GetImpl(bufferGL);
                     mCurrentElementArrayBufferResource = bufferVk;
                     mCurrentElementArrayBufferHandle   = bufferVk->getVkBuffer().getHandle();
-                    mCurrentElementArrayBufferOffset   = 0;
                 }
                 else
                 {
                     mCurrentElementArrayBufferResource = nullptr;
                     mCurrentElementArrayBufferHandle   = VK_NULL_HANDLE;
-                    mCurrentElementArrayBufferOffset   = 0;
                 }
+
+                mCurrentElementArrayBufferOffset = 0;
+                mLineLoopBufferFirstIndex.reset();
+                mLineLoopBufferLastIndex.reset();
                 mIndexBufferDirty         = true;
                 mDirtyLineLoopTranslation = true;
                 break;