Error on saving product data- found why

[satkauskas]

I found, that having special simblos in tags, meta tags leads to NOT saving product error. Even more, its not shown as error. Everything is saved, but after refresh - its not showing the updates in product card in admin.

It was due to import, but it also showed no error at all. I found, that tags, meta tags, contained:   /   ,   .  dots, slashes, and ,  ,   - blank tags. When I disabled that column import - now product saving works OK. 

I tried on 1.7.4.2, on 1.7.3. fresh  installs. Same bug. Why bug? because while importing - it shows no error for tags, and later on - even debug mode is not showing any errors.