add some defensive coding

Author: sawka

emain/emain-ipc.ts

@@ -209,7 +209,7 @@ export function initIpcHandlers() {
 
     electron.ipcMain.on("webview-image-contextmenu", (event: electron.IpcMainEvent, payload: { src: string }) => {
         const menu = new electron.Menu();
-        const win = getWaveWindowByWebContentsId(event.sender.hostWebContents.id);
+        const win = getWaveWindowByWebContentsId(event.sender.hostWebContents?.id);
         if (win == null) {
             return;
         }
@@ -353,6 +353,7 @@ export function initIpcHandlers() {
             const png = PNG.sync.read(overlayBuffer);
             const color = fac.prepareResult(fac.getColorFromArray4(png.data));
             const ww = getWaveWindowByWebContentsId(event.sender.id);
+            if (ww == null) return;
             ww.setTitleBarOverlay({
                 color: unamePlatform === "linux" ? color.rgba : "#00000000",
                 symbolColor: color.isDark ? "white" : "black",

emain/emain-tabview.ts

@@ -109,6 +109,9 @@ function computeBgColor(fullConfig: FullConfigType): string {
 const wcIdToWaveTabMap = new Map<number, WaveTabView>();
 
 export function getWaveTabViewByWebContentsId(webContentsId: number): WaveTabView {
+    if (webContentsId == null) {
+        return null;
+    }
     return wcIdToWaveTabMap.get(webContentsId);
 }
 
@@ -313,6 +316,9 @@ export async function getOrCreateWebViewForTab(waveWindowId: string, tabId: stri
     tabView.webContents.on("will-frame-navigate", shFrameNavHandler);
     tabView.webContents.on("did-attach-webview", (event, wc) => {
         wc.setWindowOpenHandler((details) => {
+            if (wc == null || wc.isDestroyed() || tabView.webContents == null || tabView.webContents.isDestroyed()) {
+                return { action: "deny" };
+            }
             tabView.webContents.send("webview-new-window", wc.id, details);
             return { action: "deny" };
         });

emain/emain-window.ts

@@ -674,6 +674,9 @@ export function getWaveWindowByTabId(tabId: string): WaveBrowserWindow {
 }
 
 export function getWaveWindowByWebContentsId(webContentsId: number): WaveBrowserWindow {
+    if (webContentsId == null) {
+        return null;
+    }
     const tabView = getWaveTabViewByWebContentsId(webContentsId);
     if (tabView == null) {
         return null;