Patch to goprotobuf for issue #32 (https://code.google.com/p/goprotobuf/issues/detail?id=32).

goprotobuf.patch

diff -r 61664b8425f3 protoc-gen-go/descriptor/descriptor.pb.go
--- a/protoc-gen-go/descriptor/descriptor.pb.go	Fri Oct 11 10:08:35 2013 +1100
+++ b/protoc-gen-go/descriptor/descriptor.pb.go	Sat Nov 23 23:39:44 2013 +0800
@@ -682,7 +682,8 @@
 	OptimizeFor               *FileOptions_OptimizeMode `protobuf:"varint,9,opt,name=optimize_for,enum=google.protobuf.FileOptions_OptimizeMode,def=1" json:"optimize_for,omitempty"`
 	// Sets the Go package where structs generated from this .proto will be
 	// placed.  There is no default.
-	GoPackage *string `protobuf:"bytes,11,opt,name=go_package" json:"go_package,omitempty"`
+	GoPackage    *string `protobuf:"bytes,11,opt,name=go_package" json:"go_package,omitempty"`
+	GoImportPath *string `protobuf:"bytes,12,opt,name=go_import_path" json:"go_import_path,omitempty"`
 	// Should generic services be generated in each language?  "Generic" services
 	// are not specific to any particular RPC system.  They are generated by the
 	// main code generators in each language (without additional plugins).
@@ -769,6 +770,13 @@
 	return ""
 }
 
+func (m *FileOptions) GetGoImportPath() string {
+	if m != nil && m.GoImportPath != nil {
+		return *m.GoImportPath
+	}
+	return ""
+}
+
 func (m *FileOptions) GetCcGenericServices() bool {
 	if m != nil && m.CcGenericServices != nil {
 		return *m.CcGenericServices
diff -r 61664b8425f3 protoc-gen-go/generator/generator.go
--- a/protoc-gen-go/generator/generator.go	Fri Oct 11 10:08:35 2013 +1100
+++ b/protoc-gen-go/generator/generator.go	Sat Nov 23 23:39:44 2013 +0800
@@ -45,6 +45,7 @@
 	"log"
 	"os"
 	"path"
+	"reflect"
 	"strconv"
 	"strings"
 	"unicode"
@@ -251,10 +252,16 @@
 // or the input file name.
 func (d *FileDescriptor) goPackageName() (name string, explicit bool) {
 	// Does the file have a "go_package" option?
-	if opts := d.Options; opts != nil {
+	opts := d.Options
+	if opts != nil {
 		if pkg := opts.GetGoPackage(); pkg != "" {
 			return pkg, true
 		}
+		if p := opts.GetGoImportPath(); p != "" {
+			if i := strings.LastIndex(p, "/"); i >= 0 {
+				return p[i+1:], true
+			}
+		}
 	}
 
 	// Does the file have a package clause?
@@ -491,9 +498,24 @@
 	if pkg == g.packageName {
 		return ""
 	}
+	opts := obj.File().Options
+
+	if !isNilInterface(opts) && !isNilInterface(opts.GoImportPath) &&
+		!isNilInterface(g.file) && !isNilInterface(g.file.Options) &&
+		!isNilInterface(g.file.Options.GoImportPath) &&
+		*opts.GoImportPath == *g.file.Options.GoImportPath {
+		return ""
+	}
 	return pkg + "."
 }
 
+// isNilInterface is a helper function that checks for the nullity of an interface.
+// An interface with type non-nil and value nil is still considered nil.
+// Refer to http://golang.org/doc/faq#nil_error for more explanation.
+func isNilInterface(v interface{}) bool {
+	return v == nil || !reflect.ValueOf(v).Elem().IsValid()
+}
+
 // For each input file, the unique package name to use, underscored.
 var uniquePackageName = make(map[*descriptor.FileDescriptorProto]string)
 
@@ -1096,7 +1118,14 @@
 			continue
 		}
 		if _, ok := g.usedPackages[fd.PackageName()]; ok {
-			g.P("import ", fd.PackageName(), " ", strconv.Quote(filename))
+			if opts := fd.Options; !isNilInterface(opts) && !isNilInterface(opts.GoImportPath) {
+				if !isNilInterface(g.file.Options) &&
+					(isNilInterface(g.file.Options.GoImportPath) || *g.file.Options.GoImportPath != *opts.GoImportPath) {
+					g.P("import ", fd.PackageName(), " ", strconv.Quote(*opts.GoImportPath))
+				}
+			} else {
+				g.P("import ", fd.PackageName(), " ", strconv.Quote(filename))
+			}
 		} else {
 			// TODO: Re-enable this when we are more feature-complete.
 			// For instance, some protos use foreign field extensions, which we don't support.