Index: log4j-core/src/main/java/org/apache/logging/log4j/core/appender/rolling/RollingFileManager.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- log4j-core/src/main/java/org/apache/logging/log4j/core/appender/rolling/RollingFileManager.java	(revision 84cd5d4e1460bec390f58ca01585ccb4973ab10d)
+++ log4j-core/src/main/java/org/apache/logging/log4j/core/appender/rolling/RollingFileManager.java	(date 1582640668972)
@@ -289,14 +289,26 @@
         if (!hasOutputStream() && !isCreateOnDemand()) {
             return;
         }
-        if (rollover(rolloverStrategy)) {
-            try {
-                size = 0;
-                initialTime = System.currentTimeMillis();
-                createFileAfterRollover();
-            } catch (final IOException e) {
-                logError("Failed to create file after rollover", e);
+
+        boolean interrupted = Thread.interrupted(); // clear interrupted state
+        try {
+            if (interrupted) {
+                LOGGER.warn("RollingFileManager cleared thread interrupted state, continue to rollover");
+            }
+
+            if (rollover(rolloverStrategy)) {
+                try {
+                    size = 0;
+                    initialTime = System.currentTimeMillis();
+                    createFileAfterRollover();
+                } catch (final IOException e) {
+                    logError("Failed to create file after rollover", e);
+                }
             }
+        } finally {
+            if (interrupted) { // restore interrupted state
+                Thread.currentThread().interrupt();
+            }
         }
     }
 
Index: log4j-core/src/test/java/org/apache/logging/log4j/core/appender/rolling/RollingFileAppenderInterruptedThreadTest.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- log4j-core/src/test/java/org/apache/logging/log4j/core/appender/rolling/RollingFileAppenderInterruptedThreadTest.java	(date 1582708093876)
+++ log4j-core/src/test/java/org/apache/logging/log4j/core/appender/rolling/RollingFileAppenderInterruptedThreadTest.java	(date 1582708093876)
@@ -0,0 +1,78 @@
+package org.apache.logging.log4j.core.appender.rolling;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.Logger;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.appender.ConsoleAppender;
+import org.apache.logging.log4j.core.appender.RollingFileAppender;
+import org.apache.logging.log4j.core.config.Configurator;
+import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilderFactory;
+import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;
+import org.apache.logging.log4j.junit.CleanFolders;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.io.File;
+
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.instanceOf;
+
+/**
+ * Tests https://issues.apache.org/jira/browse/LOG4J2-1798
+ */
+public class RollingFileAppenderInterruptedThreadTest {
+
+    private static final String ROLLING_APPENDER_FILES_DIR =
+            "target/" + RollingFileAppenderInterruptedThreadTest.class.getSimpleName();
+
+    @Rule
+    public CleanFolders cleanFolders = new CleanFolders(true, false, 3, ROLLING_APPENDER_FILES_DIR);
+
+    LoggerContext loggerContext;
+
+    @Before
+    public void setUp() {
+        ConfigurationBuilder<BuiltConfiguration> builder = ConfigurationBuilderFactory.newConfigurationBuilder();
+        builder.setConfigurationName("LOG4J2-1798 test");
+
+        builder.add(builder.newAppender("consoleLog", "Console")
+                .addAttribute("target", ConsoleAppender.Target.SYSTEM_ERR));
+
+        builder.add(builder.newAppender("fileAppender", "RollingFile")
+                .addAttribute("filePattern", ROLLING_APPENDER_FILES_DIR + "/file-%i.log")
+                .add(builder.newLayout("PatternLayout").addAttribute("pattern", "%msg%n"))
+                .addComponent(builder.newComponent("SizeBasedTriggeringPolicy")
+                        .addAttribute("size", "20B"))); // relatively small amount to trigger rotation quickly
+
+        builder.add(builder.newRootLogger(Level.INFO)
+                .add(builder.newAppenderRef("consoleLog"))
+                .add(builder.newAppenderRef("fileAppender")));
+
+        loggerContext = Configurator.initialize(builder.build());
+    }
+
+    @After
+    public void tearDown() {
+        Configurator.shutdown(loggerContext);
+        loggerContext = null;
+    }
+
+    @Test
+    public void testRolloverInInterruptedThread() {
+        Logger logger = loggerContext.getLogger(getClass().getName());
+
+        Assert.assertThat(logger.getAppenders().values(), hasItem(instanceOf(RollingFileAppender.class)));
+
+        logger.info("Sending logging event 1"); // send first event to initialize rollover system
+
+        Thread.currentThread().interrupt(); // mark thread as interrupted
+        logger.info("Sending logging event 2"); // send second event to trigger rotation, expecting 2 files in result
+
+        Assert.assertTrue(new File(ROLLING_APPENDER_FILES_DIR, "file-1.log").exists());
+        Assert.assertTrue(new File(ROLLING_APPENDER_FILES_DIR, "file-2.log").exists());
+    }
+}