}
}

type panicReader struct{ panic bool }

func (r panicReader) Read(p []byte) (int, error) {
	if r.panic {
		panic("oops")
	}
	return 0, io.EOF
}

// Make sure that an empty Buffer remains empty when
// it is "grown" before a Read that panics
func TestReadFromPanicReader(t *testing.T) {

	// First verify non-panic behaviour
	var buf Buffer

At that point, the program is terminated and the error
condition is reported, including the value of the argument to <code>panic</code>.
This termination sequence is called <i>panicking</i>.
</p>

<pre>
panic(42)
panic("unreachable")
panic(Error("cannot parse"))
</pre>

<p>
The <code>recover</code> function allows a program to manage behavior
of a panicking goroutine.

	b, err := hex.DecodeString(s)
	if err != nil {
		panic(err)
	}
	return b
}

func returnBigZipBytes() (r io.ReaderAt, size int64) {
	b := biggestZipBytes()
	for i := 0; i < 2; i++ {
		r, err := NewReader(bytes.NewReader(b), int64(len(b)))
		if err != nil {
			panic(err)
		}
		f, err := r.File[0].Open()
		if err != nil {
			panic(err)
		}
		b, err = io.ReadAll(f)

			t.Fatalf("stdPackages contains unexpected package %s", pkg)
		}
	}
}

func TestIssue64958(t *testing.T) {
	defer func() {
		if x := recover(); x != nil {
			t.Errorf("expected no panic; recovered %v", x)
		}
	}()

	testenv.MustHaveGoBuild(t)

	for _, context := range contexts {
		w := NewWalker(context, "testdata/src/issue64958")
		pkg, err := w.importFrom("p", "", 0)

	uintptr_t _cgo_wait_runtime_init_done(void) { return 0; }
	void _cgo_release_context(uintptr_t ctxt) { }
	char* _cgo_topofstack(void) { return (char*)0; }
	void _cgo_allocate(void *a, int c) { }
	void _cgo_panic(void *a, int c) { }
	void _cgo_reginit(void) { }

The extra functions here are stubs to satisfy the references in the C
code generated for gcc. The build process links this stub, along with

The [GODEBUG History](#history) gives the exact defaults for each Go toolchain version.
For example, Go 1.21 introduces the `panicnil` setting,
controlling whether `panic(nil)` is allowed;
it defaults to `panicnil=0`, making `panic(nil)` a run-time error.
Using `panicnil=1` restores the behavior of Go 1.20 and earlier.

When compiling a work module or workspace that declares

	n, err := b.Read(rdbuf)
	if err != nil {
		panic(err)
	}
	fmt.Println(n)
	fmt.Println(b.String())
	fmt.Println(string(rdbuf))
	// Output:
	// 1
	// bcde
	// a
}

func ExampleBuffer_ReadByte() {
	var b bytes.Buffer
	b.Grow(64)
	b.Write([]byte("abcde"))
	c, err := b.ReadByte()
	if err != nil {
		panic(err)
	}
	fmt.Println(c)
	fmt.Println(b.String())

func close(c chan<- Type)

// The panic built-in function stops normal execution of the current
// goroutine. When a function F calls panic, normal execution of F stops
// immediately. Any functions whose execution was deferred by F are run in
// the usual way, and then F returns to its caller. To the caller G, the
// invocation of F then behaves like a call to panic, terminating G's

At that point, the program is terminated and the error
condition is reported, including the value of the argument to <code>panic</code>.
This termination sequence is called <i>panicking</i>.
</p>

<pre>
panic(42)
panic("unreachable")
panic(Error("cannot parse"))
</pre>

<p>
The <code>recover</code> function allows a program to manage behavior
of a panicking goroutine.

	if count == 0 {
		return []byte{}
	}

	// Since we cannot return an error on overflow,
	// we should panic if the repeat will generate an overflow.
	// See golang.org/issue/16237.
	if count < 0 {
		panic("bytes: negative Repeat count")
	}
	if len(b) >= maxInt/count {
		panic("bytes: Repeat output length overflow")
	}
	n := len(b) * count

	if len(b) == 0 {
		return []byte{}
	}