Bug 1446343 part 2 - Convert size attributes to outer size for sessionstore. r=mikedeboer

MozReview-Commit-ID: FS6yrGggD7o

--HG--
extra : rebase_source : c4b5c404292dd2c70d2c2933cdd429e903012143

browser/components/sessionstore/SessionStore.jsm

@@ -4345,23 +4345,41 @@ var SessionStoreInternal = {
       }
     }
 
-    var dimension;
-    switch (aAttribute) {
-    case "width":
-      dimension = aWindow.outerWidth;
-      break;
-    case "height":
-      dimension = aWindow.outerHeight;
-      break;
-    default:
-      dimension = aAttribute in aWindow ? aWindow[aAttribute] : "";
-      break;
+    // We want to persist the size / position in normal state, so that
+    // we can restore to them even if the window is currently maximized
+    // or minimized. However, attributes on window object only reflect
+    // the current state of the window, so when it isn't in the normal
+    // sizemode, their values aren't what we want the window to restore
+    // to. In that case, try to read from the attributes of the root
+    // element first instead.
+    if (aWindow.windowState != aWindow.STATE_NORMAL) {
+      let docElem = aWindow.document.documentElement;
+      let attr = parseInt(docElem.getAttribute(aAttribute), 10);
+      if (attr) {
+        if (aAttribute != "width" && aAttribute != "height") {
+          return attr;
+        }
+        // Width and height attribute report the inner size, but we want
+        // to store the outer size, so add the difference.
+        let xulWin = aWindow.getInterface(Ci.nsIDocShell)
+                            .treeOwner
+                            .QueryInterface(Ci.nsIInterfaceRequestor)
+                            .getInterface(Ci.nsIXULWindow);
+        let diff = aAttribute == "width"
+          ? xulWin.outerToInnerWidthDifferenceInCSSPixels
+          : xulWin.outerToInnerHeightDifferenceInCSSPixels;
+        return attr + diff;
+      }
     }
 
-    if (aWindow.windowState == aWindow.STATE_NORMAL) {
-      return dimension;
+    switch (aAttribute) {
+    case "width":
+      return aWindow.outerWidth;
+    case "height":
+      return aWindow.outerHeight;
+    default:
+      return aAttribute in aWindow ? aWindow[aAttribute] : "";
     }
-    return aWindow.document.documentElement.getAttribute(aAttribute) || dimension;
   },
 
   /**

browser/components/sessionstore/test/browser.ini

@@ -269,4 +269,4 @@ skip-if = !crashreporter || !e10s # Tabs can't crash without e10s
 [browser_cookies_legacy.js]
 [browser_cookies_privacy.js]
 [browser_speculative_connect.js]
-
+[browser_1446343-windowsize.js]

browser/components/sessionstore/test/browser_1446343-windowsize.js

@@ -0,0 +1,39 @@
+add_task(async function test() {
+  const win = await BrowserTestUtils.openNewBrowserWindow();
+
+  async function changeSizeMode(mode) {
+    let promise = BrowserTestUtils.waitForEvent(win, "sizemodechange");
+    win[mode]();
+    await promise;
+  }
+  if (win.windowState != win.STATE_NORMAL) {
+    await changeSizeMode("restore");
+  }
+
+  const {outerWidth, outerHeight, screenX, screenY} = win;
+  function checkCurrentState(sizemode) {
+    let state = JSON.parse(ss.getWindowState(win));
+    let winState = state.windows[0];
+    let msgSuffix = ` should match on ${sizemode} mode`;
+    is(winState.width, outerWidth, "width" + msgSuffix);
+    is(winState.height, outerHeight, "height" + msgSuffix);
+    // The position attributes seem to be affected on macOS when the
+    // window gets maximized, so skip checking them for now.
+    if (AppConstants.platform != "macosx" || sizemode == "normal") {
+      is(winState.screenX, screenX, "screenX" + msgSuffix);
+      is(winState.screenY, screenY, "screenY" + msgSuffix);
+    }
+    is(winState.sizemode, sizemode, "sizemode should match");
+  }
+
+  checkCurrentState("normal");
+
+  await changeSizeMode("maximize");
+  checkCurrentState("maximized");
+
+  await changeSizeMode("minimize");
+  checkCurrentState("minimized");
+
+  // Clean up.
+  await BrowserTestUtils.closeWindow(win);
+});