make t-set works with t-props

test by aku, fix by ged

src/qweb.ts

@@ -511,7 +511,7 @@ export class QWeb {
     }
   }
 
-  _formatExpression(e: string): string {
+  _formatExpression(e: string, ctx?: Context): string {
     if (e in this.exprCache) {
       return this.exprCache[e];
     }
@@ -537,7 +537,10 @@ export class QWeb {
       } else if (c.match(/\W/) && invar.length) {
         // TODO: Should check for possible spaces before dot
         if (chars[invarPos - 1] !== "." && RESERVED_WORDS.indexOf(invar) < 0) {
-          invar = WORD_REPLACEMENT[invar] || "context['" + invar + "']";
+          invar =
+            WORD_REPLACEMENT[invar] ||
+            (ctx && invar in ctx.variables && ctx.variables[invar]) ||
+            "context['" + invar + "']";
         }
         r += invar;
         invar = "";
@@ -847,7 +850,7 @@ const widgetDirective: Directive = {
             if (!val) {
               val = key;
             }
-            return `${key}: ${qweb._formatExpression(val)}`;
+            return `${key}: ${qweb._formatExpression(val, ctx)}`;
           })
           .join(",");
         props = "{" + innerProp + "}";

tests/component.test.ts

@@ -787,6 +787,27 @@ describe("props evaluation (with t-props directive)", () => {
     await widget.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>hello aaron</span></div>");
   });
+
+  test("t-set works with t-props", async () => {
+    class Parent extends Widget {
+      inlineTemplate = `
+        <div>
+          <t t-set="val" t-value="42"/>
+          <t t-widget="child" t-props="{val:val}"/>
+        </div>`;
+        widgets = { child: Child }
+    }
+    class Child extends Widget {
+      inlineTemplate = `
+        <span>
+          <t t-esc="props.val"/>
+        </span>`;
+    }
+
+    const widget = new Parent(env);
+    await widget.mount(fixture);
+    expect(normalize(fixture.innerHTML)).toBe("<div><span>42</span></div>");
+  });
 });
 
 describe("other directives with t-widget", () => {