[bugfix] Avoid NPE under rare circumstances in translating a Java Exception to an XQuery Error Code.

This is a regression that was introduced in 91ab58f.
Closes #7

Author: adamretter

exist-core/pom.xml

@@ -924,6 +924,7 @@
                                 <include>src/main/java/org/exist/xquery/ErrorCodes.java</include>
                                 <include>src/main/java/org/exist/xquery/FunctionFactory.java</include>
                                 <include>src/main/java/org/exist/xquery/Optimizer.java</include>
+                                <include>src/main/java/org/exist/xquery/TryCatchExpression.java</include>
                                 <include>src/main/java/org/exist/xquery/UserDefinedFunction.java</include>
                                 <include>src/main/java/org/exist/xquery/XPathUtil.java</include>
                                 <include>src/main/java/org/exist/xquery/XQueryContext.java</include>
@@ -1233,6 +1234,7 @@
                                 <exclude>src/main/java/org/exist/xquery/Materializable.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/NameTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/Optimizer.java</exclude>
+                                <exclude>src/main/java/org/exist/xquery/TryCatchExpression.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/UserDefinedFunction.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/WatchdogTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/XPathUtil.java</exclude>

exist-core/src/main/java/org/exist/xquery/ErrorCodes.java

@@ -48,6 +48,8 @@
 import org.exist.Namespaces;
 import org.exist.dom.QName;
 
+import javax.annotation.Nullable;
+
 /**
  *
  * @author aretter
@@ -295,14 +297,14 @@ public class ErrorCodes {
     public static class ErrorCode {
 
         private final QName errorQName;
-        private final String description;
+        private @Nullable final String description;
 
-        public ErrorCode(String code, String description) {
+        public ErrorCode(final String code, @Nullable final String description) {
             this.errorQName = new QName(code, Namespaces.EXIST_XQUERY_XPATH_ERROR_NS, Namespaces.EXIST_XQUERY_XPATH_ERROR_PREFIX);
             this.description = description;
         }
 
-        public ErrorCode(QName errorQName, String description) {
+        public ErrorCode(final QName errorQName, final String description) {
             this.errorQName = errorQName;
             this.description = description;
         }
@@ -313,10 +315,10 @@ public QName getErrorQName() {
 
         @Override
         public String toString() {
-            return "(" + errorQName.getNamespaceURI() + "#" + errorQName.getLocalPart() + "):" + description;
+            return "(" + errorQName.toString() + "): " + description;
         }
 
-        public String getDescription(){
+        public @Nullable String getDescription(){
             return description;
         }
     }
@@ -337,12 +339,21 @@ private EXistErrorCode(String code, String description) {
 
     public static class JavaErrorCode extends ErrorCode {
 
-        public JavaErrorCode(final Throwable throwable) {
-            super(new QName(
-                        throwable.getClass().getName(),
-                        Namespaces.EXIST_JAVA_BINDING_NS,
-                        Namespaces.EXIST_JAVA_BINDING_NS_PREFIX),
-                  throwable.getMessage() != null ? throwable.getMessage() : throwable.getCause().getMessage());
+        private JavaErrorCode(final QName errorQName, @Nullable final String description) {
+            super(errorQName, description);
+        }
+
+        public static JavaErrorCode fromThrowable(final Throwable throwable) {
+            final QName errorQName = new QName(throwable.getClass().getName(), Namespaces.EXIST_JAVA_BINDING_NS, Namespaces.EXIST_JAVA_BINDING_NS_PREFIX);
+            @Nullable final String description;
+            if (throwable.getMessage() != null) {
+                description = throwable.getMessage();
+            } else if (throwable.getCause() != null) {
+                description = throwable.getCause().getMessage();
+            } else {
+                description = null;
+            }
+            return new JavaErrorCode(errorQName, description);
         }
     }
 }

exist-core/src/main/java/org/exist/xquery/JavaBinding.java

@@ -558,7 +558,7 @@ public Sequence eval(final Sequence[] args, final Sequence contextSequence) thro
             return XPathUtil.javaObjectToXPath(javaResult, context, true, false, false, this);
 
         } catch (final IllegalAccessException | InvocationTargetException | InstantiationException | IllegalArgumentException e) {
-            throw new XPathException(this, new ErrorCodes.JavaErrorCode(e), e.getMessage());
+            throw new XPathException(this, ErrorCodes.JavaErrorCode.fromThrowable(e), e.getMessage());
         }
     }
 

exist-core/src/main/java/org/exist/xquery/TryCatchExpression.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -166,7 +190,7 @@ public Sequence eval(final Sequence contextSequence, final Item contextItem) thr
                 }
             } else {
                 // Get errorcode from all other errors and exceptions
-                errorCode = new JavaErrorCode(throwable);
+                errorCode = JavaErrorCode.fromThrowable(throwable);
             }
 
             // We need the qname in the end
@@ -414,7 +438,7 @@ private ErrorCode extractErrorCode(final XPathException xpe)  {
         }
 
         // Fallback, create java error
-        return new ErrorCodes.JavaErrorCode(retVal);
+        return JavaErrorCode.fromThrowable(retVal);
     }
 
     @Override

extensions/modules/exi/pom.xml

@@ -139,9 +139,9 @@
                             -->
                             <header>${project.parent.relativePath}/../../elemental-parent/elemental-LGPL-21-ONLY-license.template.txt</header>
                             <excludes>
+                                <exclude>exi-functions-demo.xql</exclude>
                                 <exclude>pom.xml</exclude>
                                 <exclude>src/**</exclude>
-                                <exclude>exi-functions-demo.xql</exclude>
                             </excludes>
                         </licenseSet>
 
@@ -160,6 +160,8 @@
                             </multi>
                             <includes>
                                 <include>pom.xml</include>
+                                <include>src/main/java/org/exist/xquery/modules/exi/DecodeExiFunction.java</include>
+                                <include>src/main/java/org/exist/xquery/modules/exi/EncodeExiFunction.java</include>
                             </includes>
                         </licenseSet>
 
@@ -170,6 +172,8 @@
                             <header>${project.parent.relativePath}/../../exist-parent/existdb-LGPL-21-license.template.txt</header>
                             <excludes>
                                 <exclude>pom.xml</exclude>
+                                <exclude>src/main/java/org/exist/xquery/modules/exi/DecodeExiFunction.java</exclude>
+                                <exclude>src/main/java/org/exist/xquery/modules/exi/EncodeExiFunction.java</exclude>
                             </excludes>
                         </licenseSet>
 

extensions/modules/exi/src/main/java/org/exist/xquery/modules/exi/DecodeExiFunction.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -125,8 +149,8 @@ public Sequence eval(Sequence[] args, Sequence contextSequence)
 				context.popDocumentContext();
 			}
 		}
-		catch(EXIException | SAXException | IOException exie) {
-			throw new XPathException(this, new JavaErrorCode(exie.getCause()), exie.getMessage());
+		catch(final EXIException | SAXException | IOException exie) {
+			throw new XPathException(this, JavaErrorCode.fromThrowable(exie.getCause()), exie.getMessage());
 		}
 	}
 

extensions/modules/exi/src/main/java/org/exist/xquery/modules/exi/EncodeExiFunction.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -114,8 +138,8 @@ public Sequence eval(Sequence[] args, Sequence contextSequence)
 			// TODO - test!
 			throw new XPathException(this, ErrorCodes.FODC0002, ioex.getMessage());
 		}
-		catch(EXIException | SAXException exie) {
-			throw new XPathException(this, new JavaErrorCode(exie.getCause()), exie.getMessage());
+		catch(final EXIException | SAXException exie) {
+			throw new XPathException(this, JavaErrorCode.fromThrowable(exie.getCause()), exie.getMessage());
 		}
 	}