When calling gl.GetAttachedShaders(program) on a program that has no shaders attached, an avoidable panic occurs.

panic: runtime error: index out of range

goroutine 21 [running]:
golang.org/x/mobile/gl.GetAttachedShaders(0x1, 0x0, 0x0, 0x0)
    /Users/shazow/local/go1.5/src/golang.org/x/mobile/gl/gl.go:860 +0x1d0

We get the number of attached shaders with shadersLen := GetProgrami(p, ATTACHED_SHADERS) and allocate the buffer based on that number, but we never check if it's zero.

Simplest fix would be something like this:

func GetAttachedShaders(p Program) []Shader {
    shadersLen := GetProgrami(p, ATTACHED_SHADERS)
+   if shadersLen == 0 {
+       return []Shader{}
+   }
    var n C.GLsizei
    buf := make([]C.GLuint, shadersLen)
    ...

This is on go version devel +71832ff Fri Jul 3 21:39:04 2015 +0000 darwin/amd64 with the latest x/mobile (9865dd0).

(Happy to do a CL if that would be more convenient.)