UIWebView-BUG-fetch-silence-when-foucs

summery

In UIWebView, fetch is buggy inside onfocus, it may just be silent and call neither callback.

demo

open demo page : https://weiying-shenzhen.github.io/UIWebview-BUG-fetch-silence-when-foucs/ ,

( source code link here )

focus on input, and blur

and do above line again

results:

chrome	ios UIWebView

clearly ios UIWebView is lack of 3 done log after second focus. (no error log either)

the 3 fetch at second focus seem just silent after start, neither success nor error callback is triggered.

environment

iOS 10.3, 10.3.1 and 10.3.2, earlier version not tested.

P.S.

Not occurs on WKWebView

- 发现过程


发现手Q在输入框 focus 时调用原生 fetch 获取数据，有大概率会出现数据返回但没有触发 fetch 回调的情况

后经过对比和其他程序测试，认为是UIWebview的bug

- 复现环境
IOS版本：10.3.1
手Q版本：v7.0.1.407

- 复现步骤
1. 使用手Q打开[示例页面](https://weiying-shenzhen.github.io/UIWebview-BUG-fetch-silence-when-foucs/)
2. 点击页面的输入框触发 focus 和 fetch
3. 符合复现环境的机型，会停留在 fetch start，但后端数据其实已经返回了