From 4cd1b2f6d92e7c429fcedeff31a40bc0532ed96c Mon Sep 17 00:00:00 2001
From: Richard Lehane <richard.lehane@gmail.com>
Date: Thu, 15 Oct 2015 21:28:42 +1100
Subject: [PATCH] add Null type

---
 README.md        |  4 ++--
 msoleps.go       | 12 ++++++++++++
 sets.go          | 11 +++++++++--
 types/numeric.go | 14 ++++++++++++++
 types/types.go   |  1 +
 5 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index abec33e..f49eba5 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Example usage:
         if oerr := props.Reset(doc); oerr != nil {
           log.Fatal(oerr)
         }
-        for prop := range props.Property {
+        for _, prop := range props.Property {
           fmt.Printf("Name: %s; Type: %s; Value: %v", prop.Name, prop.Type(), prop)
         }
       }
@@ -22,6 +22,6 @@ Example usage:
 
 Install with `go get github.com/richardlehane/msoleps`
 
-*Status: currently works for simple property sets like SummaryInformation. Not all types implemented yet (e.g. Vector, Array). Property set bags not implemented yet*
+*Status: currently works for simple property sets like SummaryInformation. Not all types implemented yet (e.g. Array). Property set bags not implemented yet*
 
 [![Build Status](https://travis-ci.org/richardlehane/msoleps.png?branch=master)](https://travis-ci.org/richardlehane/msoleps)
\ No newline at end of file
diff --git a/msoleps.go b/msoleps.go
index 190dbbc..0eafd67 100644
--- a/msoleps.go
+++ b/msoleps.go
@@ -125,9 +125,15 @@ func (r *Reader) start(rdr io.Reader) error {
 			dict = make(map[uint32]string)
 		}
 	}
+	dict = addDefaults(dict)
 	for i, v := range ps.idsOffs {
 		r.Property[i] = &Property{}
 		r.Property[i].Name = dict[v.id]
+		// don't try to evaluate dictionary property
+		if v.id == 0x00000000 {
+			r.Property[i].T = types.Null{}
+			continue
+		}
 		t, _ := types.Evaluate(r.buf[int(v.offset+pss.offsetA):])
 		if t.Type() == "CodeString" {
 			cs := t.(*types.CodeString)
@@ -146,10 +152,16 @@ func (r *Reader) start(rdr io.Reader) error {
 			dict = make(map[uint32]string)
 		}
 	}
+	dict = addDefaults(dict)
 	for i, v := range psb.idsOffs {
 		i += len(ps.idsOffs)
 		r.Property[i] = &Property{}
 		r.Property[i].Name = dict[v.id]
+		// don't try to evaluate dictionary property
+		if v.id == 0x00000000 {
+			r.Property[i].T = types.Null{}
+			continue
+		}
 		t, _ := types.Evaluate(r.buf[int(v.offset+pss.offsetB):])
 		if t.Type() == "CodeString" {
 			cs := t.(*types.CodeString)
diff --git a/sets.go b/sets.go
index b079a16..0de79b8 100644
--- a/sets.go
+++ b/sets.go
@@ -16,9 +16,17 @@ package msoleps
 
 import "github.com/richardlehane/msoleps/types"
 
+func addDefaults(m map[uint32]string) map[uint32]string {
+	m[0x00000000] = "Dictionary"
+	m[0x00000001] = "CodePage"
+	m[0x80000000] = "Locale"
+	m[0x80000003] = "Behaviour"
+	return m
+
+}
+
 var propertySets map[types.Guid]map[uint32]string = map[types.Guid]map[uint32]string{
 	types.MustGuidFromString("{D5CDD502-2E9C-101B-9397-08002B2CF9AE}"): map[uint32]string{
-		0x00000001: "CodePage",
 		0x00000002: "Category",
 		0x00000003: "Presentation Format",
 		0x00000004: "Byte count",
@@ -47,7 +55,6 @@ var propertySets map[types.Guid]map[uint32]string = map[types.Guid]map[uint32]st
 		0x0000001D: "Document Version",
 	},
 	types.MustGuidFromString("{F29F85E0-4FF9-1068-AB91-08002B27B3D9}"): map[uint32]string{
-		0x00000001: "CodePage",
 		0x00000002: "Title",
 		0x00000003: "Subject",
 		0x00000004: "Author",
diff --git a/types/numeric.go b/types/numeric.go
index f510a9c..0ddc387 100644
--- a/types/numeric.go
+++ b/types/numeric.go
@@ -19,6 +19,20 @@ import (
 	"strconv"
 )
 
+type Null struct{}
+
+func (i Null) Type() string {
+	return "Null"
+}
+
+func (i Null) Length() int {
+	return 0
+}
+
+func (i Null) String() string {
+	return ""
+}
+
 type Bool bool
 
 func (i Bool) Type() string {
diff --git a/types/types.go b/types/types.go
index a2ca4fc..62f68ee 100644
--- a/types/types.go
+++ b/types/types.go
@@ -19,6 +19,7 @@ import (
 	"errors"
 )
 
+// MakeVariant is defined in vectorArray.go. It calls Evaluate, which refers to the MakeTypes map, so must add at runtime
 func init() { MakeTypes[VT_VARIANT] = MakeVariant }
 
 var (