Adjust scanning of keywordy jsx namespace names, add grammar error for jsx dotted names containing namespace names (#43104)

src/compiler/checker.ts

@@ -40728,6 +40728,7 @@ namespace ts {
         }
 
         function checkGrammarJsxElement(node: JsxOpeningLikeElement) {
+            checkGrammarJsxName(node.tagName);
             checkGrammarTypeArguments(node, node.typeArguments);
             const seen = new Map<__String, boolean>();
 
@@ -40750,6 +40751,29 @@ namespace ts {
             }
         }
 
+        function checkGrammarJsxName(node: JsxTagNameExpression) {
+            if (isPropertyAccessExpression(node)) {
+                let propName: JsxTagNameExpression = node;
+                do {
+                    const check = checkGrammarJsxNestedIdentifier(propName.name);
+                    if (check) {
+                        return check;
+                    }
+                    propName = propName.expression;
+                } while (isPropertyAccessExpression(propName));
+                const check = checkGrammarJsxNestedIdentifier(propName);
+                if (check) {
+                    return check;
+                }
+            }
+
+            function checkGrammarJsxNestedIdentifier(name: MemberName | ThisExpression) {
+                if (isIdentifier(name) && idText(name).indexOf(":") !== -1) {
+                    return grammarErrorOnNode(name, Diagnostics.JSX_property_access_expressions_cannot_include_JSX_namespace_names);
+                }
+            }
+        }
+
         function checkGrammarJsxExpression(node: JsxExpression) {
             if (node.expression && isCommaSequence(node.expression)) {
                 return grammarErrorOnNode(node.expression, Diagnostics.JSX_expressions_may_not_use_the_comma_operator_Did_you_mean_to_write_an_array);

src/compiler/diagnosticMessages.json

@@ -2674,6 +2674,10 @@
         "category": "Error",
         "code": 2632
     },
+    "JSX property access expressions cannot include JSX namespace names": {
+        "category": "Error",
+        "code": 2633
+    },
 
     "Cannot augment module '{0}' with value exports because it resolves to a non-module entity.": {
         "category": "Error",

src/compiler/scanner.ts

@@ -2335,6 +2335,7 @@ namespace ts {
                         tokenValue += ":";
                         pos++;
                         namespaceSeparator = true;
+                        token = SyntaxKind.Identifier; // swap from keyword kind to identifier kind
                         continue;
                     }
                     const oldPos = pos;