Delete OpenAL buffers with the buffer API

fix.txt

@@ -149,13 +149,13 @@ Priority 1: transport, lifecycle, and correctness
 Priority 2: protocol and data correctness
 ------------------------------------------
 
-18. UserStats FromServer fields are copied from FromClient
+[x] 18. UserStats FromServer fields are copied from FromClient
     File: gumble/gumble/handlers.go
     In handleUserStats, FromServer.Good is correct but Late/Lost/Resync read
     packet.FromClient. Use packet.FromServer for all four fields and add a
     regression test with differing values.
 
-19. Full channel link updates leave stale reverse links
+[x] 19. Full channel link updates leave stale reverse links
     File: gumble/gumble/handlers.go
     A ChannelState Links replacement assigns a new channel.Links map but does
     not remove channel from the Links maps of old peers. Remove reciprocal old

gumble/go-openal/openal/buffer.go

@@ -29,6 +29,9 @@ type Buffers []Buffer
 // NewBuffers() creates n fresh buffers.
 // Renamed, was GenBuffers.
 func NewBuffers(n int) (buffers Buffers) {
+	if n <= 0 {
+		return Buffers{}
+	}
 	buffers = make(Buffers, n)
 	C.walGenBuffers(C.ALsizei(n), unsafe.Pointer(&buffers[0]))
 	return
@@ -36,8 +39,10 @@ func NewBuffers(n int) (buffers Buffers) {
 
 // Delete() deletes the given buffers.
 func (self Buffers) Delete() {
-	n := len(self)
-	C.walDeleteBuffers(C.ALsizei(n), unsafe.Pointer(&self[0]))
+	if len(self) == 0 {
+		return
+	}
+	C.walDeleteBuffers(C.ALsizei(len(self)), unsafe.Pointer(&self[0]))
 }
 
 // Renamed, was Bufferf.
@@ -179,7 +184,7 @@ func NewBuffer() Buffer {
 // Delete() deletes a single buffer.
 // Convenience function, see DeleteBuffers().
 func (self Buffer) Delete() {
-	C.walDeleteSource(C.ALuint(self))
+	C.walDeleteBuffer(C.ALuint(self))
 }
 
 // GetFrequency() returns the frequency, in Hz, of the buffer's sample data.