I had an application with versionCode 1 and versionName = 1.0 on PlayStore.I decided to upgrade my app to versionCode 2 and versionName 1.1.However by mistake I signed it with different certificate key.
Developers android documentation mentions that if the application is upgraded with different certificate key then users will not be able to upgrade it.Realising the horror I immediately shipped another upgrade with versionCode 3 and versionName 1.2 but this time I signed it with the original certificate key(one which I used to sign the versionCode 1 and versioName 1.0).
My question is will users who installed initial version be able to upgrade now since I launched versionCode 3 with the same certificate key as their application which is installed in their devices with versionCode 1?
People who had v1 will have no problem. If you really uploaded a v2 with a different signature and someone went through the trouble of uninstalling just so they could install v2 would have to uninstall again and install v3.
What i really wonder tough it's how you uploaded an apk with a different signature. I accidentally lost my key once and didn't find out until i tried to upload an update wich i had to sign with a different key and the console blocked me from uploading because it requires all apks to have the same signature.
According to the documentation if you ever lose your key you will never be able to upload a new version and if you still desire to then you must take down the first application and give your second application a different package name.