Disable XSD validation when xsi:schemaLocation doesn't declare the

namespace for the document element root.

See #951

Signed-off-by: azerr <azerr@redhat.com>

Author: angelozerr

docs/Validation.md

@@ -417,3 +417,7 @@ If `xml.validation.resolveExternalEntities` is set to `true` (default is `false`
 Demonstration of the different behaviour:
 
 ![When using the default settings, an external entity that has an XML element as its content will not produce a validation error when nested in an element that expects character content. If `xml.validation.resolveExternalEntities` is enabled, then an error will be produced](./images/Validation/ExternalEntityResolvingDemonstration.gif)
+
+## xml.validation.schema.enabled
+
+TODO

package.json

@@ -307,10 +307,20 @@
           "markdownDescription": "Enable/disable all validation. Default is `true`.",
           "scope": "window"
         },
-        "xml.validation.schema": {
-          "type": "boolean",
-          "default": true,
-          "markdownDescription": "Enable/disable schema based validation. Default is `true`. Ignored if `#xml.validation.enabled#` is set to `false`",
+        "xml.validation.schema.enabled": {
+          "type": "string",
+          "default": "always",
+          "enum": [
+            "always",
+            "never",
+            "onValidSchema"
+          ],
+          "markdownEnumDescriptions": [
+            "Enable schema based validation.",
+            "Disable schema based validation.",
+            "Enable schema based validation only when the declared xsi:schemaLocation hint is valid for the root element."
+          ],
+          "markdownDescription": "Enable/disable schema based validation. Default is `always`. Ignored if `#xml.validation.enabled#` is set to `false`",
           "scope": "window"
         },
         "xml.validation.disallowDocTypeDecl": {