mshtml: Implement IHTMLCurrentStyle_get_margin.

dlls/mshtml/htmlcurstyle.c

@@ -739,8 +739,8 @@ static HRESULT WINAPI HTMLCurrentStyle_get_padding(IHTMLCurrentStyle *iface, BST
 static HRESULT WINAPI HTMLCurrentStyle_get_margin(IHTMLCurrentStyle *iface, BSTR *p)
 {
     HTMLCurrentStyle *This = HTMLCURSTYLE_THIS(iface);
-    FIXME("(%p)->(%p)\n", This, p);
-    return E_NOTIMPL;
+    TRACE("(%p)->(%p)\n", This, p);
+    return get_nsstyle_attr(This->nsstyle, STYLEID_MARGIN, p);
 }
 
 static HRESULT WINAPI HTMLCurrentStyle_get_accelerator(IHTMLCurrentStyle *iface, BSTR *p)

dlls/mshtml/tests/dom.c

@@ -2567,6 +2567,10 @@ static void test_current_style(IHTMLCurrentStyle *current_style)
     ok(hres == S_OK, "get_borderWidth failed: %08x\n", hres);
     SysFreeString(str);
 
+    hres = IHTMLCurrentStyle_get_margin(current_style, &str);
+    ok(hres == S_OK, "get_margin failed: %08x\n", hres);
+    SysFreeString(str);
+
     hres = IHTMLCurrentStyle_get_fontWeight(current_style, &v);
     ok(hres == S_OK, "get_fontWeight failed: %08x\n", hres);
     ok(V_VT(&v) == VT_I4, "V_VT(v) = %d\n", V_VT(&v));