"Don't directly throw Exception" System.Private.Xml (#25975)

* Don't directly throw Exception

* Don't directly throw Exception

* Don't directly throw Exception

* Don't directly throw Exception

* Fix test

Author: MarcoRossignoli

src/System.Private.Xml/src/System/Xml/Core/XmlTextReaderImplAsync.cs

@@ -3593,7 +3593,7 @@ private async Task<ValueTuple<int, int, int, bool>> ParseTextAsync_Surrogate(int
                 ThrowInvalidChar(_ps.chars, _ps.charsUsed, _ps.charPos + offset);
             }
             //should never hit here
-            throw new Exception();
+            throw new XmlException(SR.Xml_InternalError);            
         }
 
         private async Task<ValueTuple<int, int, int, bool>> ParseTextAsync_ReadData(int outOrChars, char[] chars, int pos, int rcount, int rpos, int orChars, char c)

src/System.Private.Xml/src/System/Xml/Serialization/Xmlcustomformatter.cs

@@ -77,7 +77,7 @@ internal static string FromDefaultValue(object value, string formatter)
                     return FromXmlNmTokens((string)value);
                 }
             }
-            throw new Exception(SR.Format(SR.XmlUnsupportedDefaultType, type.FullName));
+            throw new XmlException(SR.Format(SR.XmlUnsupportedDefaultType, type.FullName));
         }
 
         internal static string FromDate(DateTime value)
@@ -243,7 +243,7 @@ internal static object ToDefaultValue(string value, string formatter)
             {
                 return ToXmlNmTokens(value);
             }
-            throw new Exception(SR.Format(SR.XmlUnsupportedDefaultValue, formatter));
+            throw new XmlException(SR.Format(SR.XmlUnsupportedDefaultValue, formatter));
             //            Debug.WriteLineIf(CompModSwitches.XmlSerialization.TraceVerbose, "XmlSerialization::Unhandled default value " + value + " formatter " + formatter);
             //            return DBNull.Value;
         }

src/System.Private.Xml/src/System/Xml/Xsl/Xslt/XPathPatternBuilder.cs

@@ -321,14 +321,15 @@ public QilNode Function(string prefix, string name, IList<QilNode> args)
         }
 
         public QilNode String(string value) { return _f.String(value); }     // As argument of id() or key() function
-        public QilNode Number(double value) { return UnexpectedToken("Literal number"); }
-        public QilNode Variable(string prefix, string name) { return UnexpectedToken("Variable"); }
-
-        private QilNode UnexpectedToken(string tokenName)
+        public QilNode Number(double value)
+        {
+            //Internal Error: Literal number is not allowed in XSLT pattern outside of predicate.
+            throw new XmlException(SR.Xml_InternalError);
+        }
+        public QilNode Variable(string prefix, string name)
         {
-            string prompt = string.Format(CultureInfo.InvariantCulture, "Internal Error: {0} is not allowed in XSLT pattern outside of predicate.", tokenName);
-            Debug.Assert(false, prompt);
-            throw new Exception(prompt);
+            //Internal Error: Variable is not allowed in XSLT pattern outside of predicate.
+            throw new XmlException(SR.Xml_InternalError);
         }
 
         // -------------------------------------- Priority / Parent ---------------------------------------

src/System.Private.Xml/tests/XmlSerializer/XmlSerializerTests.RuntimeOnly.cs

@@ -1936,6 +1936,20 @@ public static void XmlReflectionImporterTest()
         Assert.False(xmp.CheckSpecified);
     }
 
+    [Fact]       
+    public static void XmlSchemaExporter_ExportMembersMapping_NotSupportedDefaultValue()
+    {
+        XmlReflectionImporter importer = new XmlReflectionImporter("http://www.contoso.com/");
+        XmlReflectionMember[] members = new XmlReflectionMember[1];
+        XmlReflectionMember member = members[0] = new XmlReflectionMember();
+        member.MemberType = typeof(TypeWithQNameArrayAsXmlAttributeInvalidDefaultValue);
+        XmlMembersMapping mappings = importer.ImportMembersMapping("root", "", members, true);
+        XmlMemberMapping xmp = mappings[0];
+        XmlSchemas schema = new XmlSchemas();
+        XmlSchemaExporter exporter = new XmlSchemaExporter(schema);
+        AssertExtensions.Throws<XmlException,Exception>(() => exporter.ExportMembersMapping(mappings));
+    }
+
     [Fact]
     public static void XmlSerializerVersionAttributeTest()
     {

src/System.Runtime.Serialization.Xml/tests/SerializationTypes.RuntimeOnly.cs

@@ -1979,6 +1979,13 @@ public class TypeWithArrayLikeXmlAttributeWithFields
         public int IntField;
     }
 
+    [XmlType(TypeName = "MyXmlType")]
+    public class TypeWithQNameArrayAsXmlAttributeInvalidDefaultValue
+    {
+        [DefaultValue("DefaultValue")]
+        public XmlQualifiedName XmlAttributeForms;
+    }
+
     [XmlType(TypeName = "MyXmlType")]
     public class TypeWithQNameArrayAsXmlAttribute
     {