582906 XSD validating multiple imports of the same schema

* xmlschemas.c: When validating a schema that includes the same file
  that has no targetNamespace defined an internal erro was thrown,
  depending on the orig namespace that should be allowed though
* test/schemas/582906-* result/schemas/582906-*: 2 tests case, one
  where this is allowed, and one where this is forbidden

result/schemas/582906-1_0_0

@@ -0,0 +1 @@
+./test/schemas/582906-1_0.xml validates

result/schemas/582906-2_0_0.err

@@ -0,0 +1 @@
+test/schemas/582906-2-prog1.xsd:9: element include: Schemas parser error : Element '{http://www.w3.org/2001/XMLSchema}include': The target namespace 'http://example.com/xml/Prog3' of the included/redefined schema 'test/schemas/582906-2-common.xsd' differs from 'http://example.com/xml/Prog1' of the including/redefining schema.

test/schemas/582906-1-common.xsd

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified">
+</xs:schema>

test/schemas/582906-1-prog1.xsd

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns="http://example.com/xml/Prog1"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Prog1">
+
+    <xs:include schemaLocation="582906-1-common.xsd"/>
+
+</xs:schema>

test/schemas/582906-1-prog2-include.xsd

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified" attributeFormDefault="unqualified"
+           xml:lang="en">
+
+    <xs:include schemaLocation="582906-1-common.xsd"/>
+
+</xs:schema>

test/schemas/582906-1-prog2.xsd

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns="http://example.com/xml/Prog2"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Prog2">
+
+    <xs:include schemaLocation="582906-1-common.xsd"/>
+
+    <xs:include schemaLocation="582906-1-prog2-include.xsd"/>
+
+</xs:schema>

test/schemas/582906-1_0.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CollectedOutput xmlns="http://example.com/xml/Aggregator"
+             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+             xsi:schemaLocation="http://example.com/xml/Aggregator
+             582906-1.xsd">5.3</CollectedOutput>

test/schemas/582906-1_0.xsd

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns="http://example.com/xml/Aggregator"
+           xmlns:prog1="http://example.com/xml/Prog1"
+           xmlns:prog2="http://example.com/xml/Prog2"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Aggregator">
+
+    <xs:import schemaLocation="582906-1-prog1.xsd"
+               namespace="http://example.com/xml/Prog1" />
+
+    <xs:import schemaLocation="582906-1-prog2.xsd"
+               namespace="http://example.com/xml/Prog2"
+               />
+
+    <xs:element name="CollectedOutput" type="xs:float"/>
+
+</xs:schema>

test/schemas/582906-2-common.xsd

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Prog3">
+</xs:schema>

test/schemas/582906-2-prog1.xsd

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns="http://example.com/xml/Prog1"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Prog1">
+
+    <xs:include schemaLocation="582906-2-common.xsd"/>
+
+</xs:schema>

test/schemas/582906-2-prog2-include.xsd

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified" attributeFormDefault="unqualified"
+           xml:lang="en">
+
+    <xs:include schemaLocation="582906-2-common.xsd"/>
+
+</xs:schema>

test/schemas/582906-2-prog2.xsd

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns="http://example.com/xml/Prog2"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Prog2">
+
+    <xs:include schemaLocation="582906-2-common.xsd"/>
+
+    <xs:include schemaLocation="582906-2-prog2-include.xsd"/>
+
+</xs:schema>

test/schemas/582906-2_0.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CollectedOutput xmlns="http://example.com/xml/Aggregator"
+             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+             xsi:schemaLocation="http://example.com/xml/Aggregator
+             582906-2-0.xsd">5.3</CollectedOutput>

test/schemas/582906-2_0.xsd

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- $Id$ -->
+<xs:schema xmlns="http://example.com/xml/Aggregator"
+           xmlns:prog1="http://example.com/xml/Prog1"
+           xmlns:prog2="http://example.com/xml/Prog2"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           targetNamespace="http://example.com/xml/Aggregator">
+
+    <xs:import schemaLocation="582906-2-prog1.xsd"
+               namespace="http://example.com/xml/Prog1" />
+
+    <xs:import schemaLocation="582906-2-prog2.xsd"
+               namespace="http://example.com/xml/Prog2"
+               />
+
+    <xs:element name="CollectedOutput" type="xs:float"/>
+
+</xs:schema>

xmlschemas.c

@@ -11039,14 +11039,15 @@ xmlSchemaParseIncludeOrRedefine(xmlSchemaParserCtxtPtr pctxt,
 	    */
 	    isChameleon = 1;
 	    if (bucket->parsed &&
-		(bucket->targetNamespace != pctxt->targetNamespace)) {
+		bucket->origTargetNamespace != NULL) {
-		/*
+		xmlSchemaCustomErr(ACTXT_CAST pctxt,
-		* This is a sanity check, I dunno yet if this can happen.
+		    XML_SCHEMAP_SRC_INCLUDE,
-		*/
+		    node, NULL,
-		PERROR_INT("xmlSchemaParseIncludeOrRedefine",
+		    "The target namespace of the included/redefined schema "
-		    "trying to use an already parsed schema for a "
+		    "'%s' has to be absent or the same as the "
-		    "different targetNamespace");
+		    "including/redefining schema's target namespace",
-		return(-1);
+		    schemaLocation, NULL);
+		goto exit_error;
 	    }
 	    bucket->targetNamespace = pctxt->targetNamespace;
 	}