fix fuzz-47093 by remove use of backslash escaping

Signed-off-by: Ceki Gulcu <[email protected]>

logback-classic/src/test/input/joran/ossfuzz/fuzz-47093.xml

@@ -0,0 +1,4 @@
+<configuration>
+  <variable scope="context" name="fuzz-47093-a" value="a\t"/>
+  <variable scope="context" name="fuzz-47093-b" value="a\\"/>  
+</configuration>

logback-classic/src/test/java/ch/qos/logback/classic/joran/JoranConfiguratorTest.java

@@ -664,8 +664,24 @@ public void ossFuzz_46697() throws JoranException  {
 
         checker.assertContainsMatch(Status.ERROR, ErrorCodes.EMPTY_MODEL_STACK);
         StatusPrinter.print(loggerContext);
-    }  
-
+    }
+
+    // https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=47093
+    // In previous versions of the code, there
+    @Test
+    public void ossFuzz_47093() throws JoranException  {
+        System.out.println("==========");
+        configure(ClassicTestConstants.JORAN_INPUT_PREFIX + "ossfuzz/fuzz-47093.xml");
+
+        assertEquals("a\\t", loggerContext.getProperty("fuzz-47093-a"));
+        assertEquals("a\\\\", loggerContext.getProperty("fuzz-47093-b"));
+
+
+        //checker.assertContainsMatch(Status.ERROR, ErrorCodes.EMPTY_MODEL_STACK);
+        StatusPrinter.print(loggerContext);
+    }
+
+
 //	@Test
 //	public void doTest() throws JoranException {
 //		int LIMIT = 0;

logback-core/src/main/java/ch/qos/logback/core/Context.java

@@ -140,6 +140,11 @@ public interface Context extends PropertyContainer {
      */
     void register(LifeCycle component);
 
+    /**
+     * Add scheduledFuture parameter to the list of known futures.
+     *
+     * @param scheduledFuture
+     */
     void addScheduledFuture(ScheduledFuture<?> scheduledFuture);
 
     SequenceNumberGenerator getSequenceNumberGenerator();

logback-core/src/main/java/ch/qos/logback/core/model/processor/PropertyModelHandler.java

@@ -68,7 +68,10 @@ public void handle(ModelInterpretationContext interpretationContext, Model model
                 }
             }
         } else if (checkValueNameAttributesSanity(propertyModel)) {
-            String value = RegularEscapeUtil.basicEscape(propertyModel.getValue());
+            // earlier versions performed Java '\' escapes for '\\' '\t' etc. Howevver, there is no
+            // need to do this. See RegularEscapeUtil.__UNUSED__basicEscape
+            String value = propertyModel.getValue();
+
             // now remove both leading and trailing spaces
             value = value.trim();
             value = interpretationContext.subst(value);

logback-core/src/main/java/ch/qos/logback/core/pattern/util/RegularEscapeUtil.java

@@ -56,6 +56,8 @@ String formatEscapeCharsForListing(String escapeChars) {
         return commaSeperatedEscapeChars.toString();
     }
 
+    // s might be path such as c:\\toto\\file.log
+    // as of version 1.3.0-beta1 this method is no longer used
     public static String basicEscape(String s) {
         char c;
         int len = s.length();
@@ -64,7 +66,7 @@ public static String basicEscape(String s) {
         int i = 0;
         while (i < len) {
             c = s.charAt(i++);
-            if (c == '\\') {
+            if (c == '\\' && i < len  ) {
                 c = s.charAt(i++);
                 if (c == 'n') {
                     c = '\n';
@@ -83,9 +85,10 @@ public static String basicEscape(String s) {
                 } else if (c == '\\') {
                     c = '\\';
                 }
+                /////
             }
             sbuf.append(c);
-        }
+        } // while
         return sbuf.toString();
     }
 }

logback-core/src/test/java/ch/qos/logback/core/pattern/util/RegularEscapeUtilTest.java

@@ -1,4 +1,39 @@
+/**
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ * Copyright (C) 1999-2022, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *   or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
+package ch.qos.logback.core.pattern.util;
+
+import org.junit.Before;
+import org.junit.Test;
+
 import static org.junit.Assert.*;
+
 public class RegularEscapeUtilTest {
-
+
+    @Before
+    public void setUp() throws Exception {
+    }
+
+    @Test
+    public void basicEscape() {
+        assertEquals("a", RegularEscapeUtil.basicEscape("a"));
+        assertEquals("a\t", RegularEscapeUtil.basicEscape("a\t"));
+        assertEquals("a\\", RegularEscapeUtil.basicEscape("a\\"));
+        assertEquals("a\\", RegularEscapeUtil.basicEscape("a\\\\"));
+    }
+
+    @Test
+    public void zbasicEscape() {
+
+    }
 }