golang：运行时错误：无效的内存地址或nil指针取消引用
I am new to golang and currently following this tutorial and source code here - http://golang.org/doc/articles/wiki/part2.go
After building this file, I am getting
calvin$ ./mywebwiki2
2012/07/23 17:12:59 http: panic serving [::1]:58820: runtime error: invalid memory address or nil pointer dereference
/usr/local/go/src/pkg/net/http/server.go:576 (0x3f202)
_func_003: buf.Write(debug.Stack())
/private/tmp/bindist454984655/go/src/pkg/runtime/proc.c:1443 (0x10c79)
/private/tmp/bindist454984655/go/src/pkg/runtime/runtime.c:128 (0x11745)
/private/tmp/bindist454984655/go/src/pkg/runtime/thread_darwin.c:418 (0x148b5)
/Users/calvin/work/gowiki/mywebwiki2.go:33 (0x2248)
viewHandler: fmt.Fprintf(w, "<h1>%s</h1><div>%s</div>", p.Title, p.Body)
/usr/local/go/src/pkg/net/http/server.go:690 (0x331ae)
HandlerFunc.ServeHTTP: f(w, r)
/usr/local/go/src/pkg/net/http/server.go:926 (0x34030)
(*ServeMux).ServeHTTP: mux.handler(r).ServeHTTP(w, r)
/usr/local/go/src/pkg/net/http/server.go:656 (0x32fc1)
(*conn).serve: handler.ServeHTTP(w, w.req)
/private/tmp/bindist454984655/go/src/pkg/runtime/proc.c:271 (0xed7f)
2012/07/23 17:12:59 http: panic serving [::1]:58821: runtime error: invalid memory address or nil pointer dereference
Any idea what I did wrong to be causing this apparent memory corruption?
There's an ignored err at line 36. The error probably says open .txt: no such file or directory if you tested in browser using URL http://localhost:8080/view/ or open foo.txt: no such file or directory if you tested in browser using URL http://localhost:8080/view/foo. In the later case there must be a file "foo.txt" in your working directory for this example code to work. After that the code seems to work for me locally.
Someone should probably fill an issue about the ignored error value.
In the tutorial, you created the file TestPage previously. Which is the page you should be navigating to when you first build the server. In the tutorial, they have you navigate to view/test instead of view/TestPage as you should which is what creates the confusion.