From 436625f83cbeabc8c6c30b7a7a099b7406f1aee8 Mon Sep 17 00:00:00 2001
From: miloyip <miloyip@gmail.com>
Date: Mon, 4 May 2015 15:02:43 +0800
Subject: [PATCH] Fix ambiguous cases in Pointer::Create()

---
 include/rapidjson/pointer.h   | 44 +++++++++++++++++------------------
 test/unittest/pointertest.cpp | 25 +++++++++++++++++++-
 2 files changed, 46 insertions(+), 23 deletions(-)

diff --git a/include/rapidjson/pointer.h b/include/rapidjson/pointer.h
index 3ba9e1c..89dfa48 100644
--- a/include/rapidjson/pointer.h
+++ b/include/rapidjson/pointer.h
@@ -305,19 +305,31 @@ public:
         ValueType* v = &root;
         bool exist = true;
         for (Token *t = tokens_; t != tokens_ + tokenCount_; ++t) {
-            if (t->index == kPointerInvalidIndex) { // object name
-                // Handling of '-' for last element of array
-                if (t->name[0] == '-' && t->length == 1) {
-                    if (!v->IsArray())
-                        v->SetArray(); // Change to Array
-                    v->PushBack(Value().Move(), allocator);
-                    v = &((*v)[v->Size() - 1]);
-                    exist = false;
-                }
-                else {
+            if (v->IsArray() && t->name[0] == '-' && t->length == 1) {
+                v->PushBack(Value().Move(), allocator);
+                v = &((*v)[v->Size() - 1]);
+                exist = false;
+            }
+            else {
+                if (t->index == kPointerInvalidIndex) { // must be object name
                     if (!v->IsObject())
                         v->SetObject(); // Change to Object
+                }
+                else { // object name or array index
+                    if (!v->IsArray() && !v->IsObject())
+                        v->SetArray(); // Change to Array
+                }
 
+                if (v->IsArray()) {
+                    if (t->index >= v->Size()) {
+                        v->Reserve(t->index + 1, allocator);
+                        while (t->index >= v->Size())
+                            v->PushBack(Value().Move(), allocator);
+                        exist = false;
+                    }
+                    v = &((*v)[t->index]);
+                }
+                else {
                     typename ValueType::MemberIterator m = v->FindMember(GenericStringRef<Ch>(t->name, t->length));
                     if (m == v->MemberEnd()) {
                         v->AddMember(Value(t->name, t->length, allocator).Move(), Value().Move(), allocator);
@@ -328,18 +340,6 @@ public:
                         v = &m->value;
                 }
             }
-            else { // array index
-                if (!v->IsArray())
-                    v->SetArray(); // Change to Array
-
-                if (t->index >= v->Size()) {
-                    v->Reserve(t->index + 1, allocator);
-                    while (t->index >= v->Size())
-                        v->PushBack(Value().Move(), allocator);
-                    exist = false;
-                }
-                v = &((*v)[t->index]);
-            }
         }
 
         if (alreadyExist)
diff --git a/test/unittest/pointertest.cpp b/test/unittest/pointertest.cpp
index 004fa22..72bfdbf 100644
--- a/test/unittest/pointertest.cpp
+++ b/test/unittest/pointertest.cpp
@@ -532,9 +532,13 @@ TEST(Pointer, Create) {
         Value* v = &Pointer("/foo/-").Create(d, d.GetAllocator());
         EXPECT_EQ(&d["foo"][1], v);
     }
+
     {
         Value* v = &Pointer("/foo/-/-").Create(d, d.GetAllocator());
-        EXPECT_EQ(&d["foo"][2][0], v);
+        // "foo/-" is a newly created null value x.
+        // "foo/-/-" finds that x is not an array, it converts x to empty object
+        // and treats - as "-" member name
+        EXPECT_EQ(&d["foo"][2]["-"], v);
     }
 
     {
@@ -1314,3 +1318,22 @@ TEST(Pointer, SwapValueByPointer_NoAllocator) {
     EXPECT_STREQ("bar", d["foo"][0].GetString());
     EXPECT_STREQ("baz", d["foo"][1].GetString());
 }
+
+TEST(Pointer, Ambiguity) {
+    {
+        Document d;
+        d.Parse("{\"0\" : [123]}");
+        EXPECT_EQ(123, Pointer("/0/0").Get(d)->GetInt());
+        Pointer("/0/a").Set(d, 456);    // Change array [123] to object {456}
+        EXPECT_EQ(456, Pointer("/0/a").Get(d)->GetInt());
+    }
+
+    {
+        Document d;
+        EXPECT_FALSE(d.Parse("[{\"0\": 123}]").HasParseError());
+        EXPECT_EQ(123, Pointer("/0/0").Get(d)->GetInt());
+        Pointer("/0/1").Set(d, 456); // 1 is treated as "1" to index object
+        EXPECT_EQ(123, Pointer("/0/0").Get(d)->GetInt());
+        EXPECT_EQ(456, Pointer("/0/1").Get(d)->GetInt());
+    }
+}