From 48d1a5ab36b0013117756b281176e12d9b5ae4fb Mon Sep 17 00:00:00 2001
From: David Arroyo <droyo@aqwari.net>
Date: Thu, 3 Jan 2019 18:18:29 -0500
Subject: [PATCH] Fix bug when modifying the last type declaration in a schema.

In the original code, there were two calls to

	root.Children = append(root.Children, t)

Because the `Children` field is a `[]xmltree.Element`, rather than an `[]*xmltree.Element`,
if the call to `append()` causes a reallocation, of the underlying array, then the `el` pointer
used within the same loop will no longer point to the current value, and updates to it will
be lost, as the added test demonstrated.

A better change would be to factor out the rearrangement of XMl such as

	<element name="foo">
	  <complexType name="foo">
	    ...
	  </complexType>
	</element>

to

	<element name="foo" type="foo"/>
	<complexType name="foo">
	  ...
	</complexType>

in a separate pass, rather than doing it in two places (the
`copyEltNamesToAnonymousTypes` and `nameAnonymousTypes` functions).
---
 xsd/parse.go                      | 16 +++++++++-------
 xsd/testdata/CopyElementName.json | 22 ++++++++++++++++++++++
 xsd/testdata/CopyElementName.xsd  | 17 +++++++++++++++++
 3 files changed, 48 insertions(+), 7 deletions(-)
 create mode 100644 xsd/testdata/CopyElementName.json
 create mode 100644 xsd/testdata/CopyElementName.xsd

diff --git a/xsd/parse.go b/xsd/parse.go
index 4edde53..c232bd1 100644
--- a/xsd/parse.go
+++ b/xsd/parse.go
@@ -189,11 +189,10 @@ func anonTypeName(n int, ns string) xml.Name {
 
 to
 
-<element name="foo" type="foo">
-  <complexType name="foo">
+<element name="foo" type="foo"/>
+<complexType name="foo">
   ...
-  </complexType>
-</element>
+</complexType>
 */
 func copyEltNamesToAnonTypes(root *xmltree.Element) {
 	used := make(map[xml.Name]struct{})
@@ -209,6 +208,7 @@ func copyEltNamesToAnonTypes(root *xmltree.Element) {
 		hasAttr("", "name"),
 		hasAnonymousType)
 
+	var newChildren []xmltree.Element
 	for _, el := range root.SearchFunc(eltWithAnonType) {
 		// Make sure we can use this element's name
 		xmlname := el.ResolveDefault(el.Attr("", "name"), tns)
@@ -221,14 +221,14 @@ func copyEltNamesToAnonTypes(root *xmltree.Element) {
 				continue
 			}
 			t.SetAttr("", "name", el.Attr("", "name"))
+			newChildren = append(newChildren, t)
 			el.SetAttr("", "type", el.Prefix(xmlname))
-
 			el.Children = append(el.Children[:i], el.Children[i+1:]...)
 			el.Content = nil
-			root.Children = append(root.Children, t)
 			break
 		}
 	}
+	root.Children = append(root.Children, newChildren...)
 }
 
 /*
@@ -261,6 +261,7 @@ func nameAnonymousTypes(root *xmltree.Element) error {
 		typeCounter int
 		updateAttr  string
 		accum       bool
+		newChildren []xmltree.Element
 	)
 	targetNS := root.Attr("", "targetNamespace")
 	for _, el := range root.SearchFunc(hasAnonymousType) {
@@ -303,12 +304,13 @@ func nameAnonymousTypes(root *xmltree.Element) error {
 			el.SetAttr("", updateAttr, qname)
 			el.Children = append(el.Children[:i], el.Children[i+1:]...)
 			el.Content = nil
-			root.Children = append(root.Children, t)
+			newChildren = append(newChildren, t)
 			if !accum {
 				break
 			}
 		}
 	}
+	root.Children = append(root.Children, newChildren...)
 	return nil
 }
 
diff --git a/xsd/testdata/CopyElementName.json b/xsd/testdata/CopyElementName.json
new file mode 100644
index 0000000..d770de4
--- /dev/null
+++ b/xsd/testdata/CopyElementName.json
@@ -0,0 +1,22 @@
+{
+  "_self": {
+    "Elements": [
+      {
+        "Name": {"Space": "tns", "Local": "TradePrice"},
+        "Type": {
+          "Base": 0,
+          "Name": {"Local": "TradePrice"},
+          "Elements": [{"Name": {"Local": "price"}, "Type": 21}]
+        }
+      },
+      {
+        "Name": {"Space": "tns", "Local": "TradePriceRequest"},
+        "Type": {
+          "Base": 0,
+          "Name": {"Local": "TradePriceRequest"},
+          "Elements": [{"Name": {"Local": "tickerSymbol"}, "Type": 38}]
+        }
+      }
+    ]
+  }
+}
diff --git a/xsd/testdata/CopyElementName.xsd b/xsd/testdata/CopyElementName.xsd
new file mode 100644
index 0000000..161c3df
--- /dev/null
+++ b/xsd/testdata/CopyElementName.xsd
@@ -0,0 +1,17 @@
+<!-- Where possible (if the type name has not been used already), anonymous types
+  declared inside an element or attribute should have the same name as their container. -->
+
+<element name="TradePrice">
+   <complexType>
+       <all>
+           <element name="price" type="float"/>
+       </all>
+   </complexType>
+</element>
+<element name="TradePriceRequest">
+   <complexType>
+       <all>
+           <element name="tickerSymbol" type="string"/>
+       </all>
+   </complexType>
+</element>