That's really stupid. I don't know what's wrong.

When I check equality of par3World.func_147439_a(par4, par5, par6) (This fuction gets Block) to Blocks.stone (This IS Block)

if (par3World.func_147439_a(par4, par5, par6) == Blocks.stone)

I knock on the stone, all goes good. As it should be!

But when I check equality of par3World.func_147439_a(par4, par5, par6).func_149739_a() to Blocks.stone.func_149739_a()

func_149739_a() gives unlocalized name of block like "tile.stone"

First of all I checked it in console

System.out.println(par3World.func_147439_a(par4, par5, par6).func_149739_a());
System.out.println(Blocks.stone.func_149739_a();

In console I saw ABSOLUTELY same strings tile.stone and tile.stone

BUUUTTT!!!!!!

if (par3World.func_147439_a(par4, par5, par6).func_149739_a() == Blocks.stone.func_149739_a())

AND THEY'RE NOT EQUAL ANYMORE!!!!!!!!! But they're equal, I know it.

 

ALSO

if (Blocks.stone.func_149739_a() == Blocks.stone.func_149739_a())

AND HE SAYS THAT THESE STRINGS ARE NOT EQUAL!!!!!!!!!!!!!!!!!!!

Please help, it's very strange.

You should use the Java function .equals()

Not very strange at all.

Oh, sorry. I didn't know. i am bad programmer, that's true. Thank tou all and sorry for my silliness.