Trim long marker properties

org.eclipse.buildship.core.test/src/main/groovy/org/eclipse/buildship/core/internal/marker/GradleMarkerManagerTest.groovy

@@ -104,6 +104,24 @@ class GradleMarkerManagerTest extends ProjectSynchronizationSpecification {
         gradleErrorMarkers[0].resource.fullPath.toPortableString() == '/'
     }
 
+    def "Long error messages are trimmed"() {
+        setup:
+        GradleMarkerManager.addError(gradleBuild, problemWithLongMessage)
+
+        expect:
+        numOfGradleErrorMarkers == 1
+        (gradleErrorMarkers[0].getAttribute(IMarker.MESSAGE) as String).length() == 65535
+    }
+
+    def "Long stacktraces are trimmed"() {
+        setup:
+        GradleMarkerManager.addError(gradleBuild, problemWithLongStacktrace)
+
+        expect:
+        numOfGradleErrorMarkers == 1
+        (gradleErrorMarkers[0].getAttribute(GradleErrorMarker.ATTRIBUTE_STACKTRACE) as String).length() == 65535
+    }
+
     private InternalGradleBuild getGradleBuild() {
         GradleCore.workspace.getBuild(project).get();
     }
@@ -119,4 +137,20 @@ class GradleMarkerManagerTest extends ProjectSynchronizationSpecification {
     private ToolingApiStatus getConnectionProblem() {
         ToolingApiStatus.from("", new GradleConnectionException(''))
     }
+
+    private ToolingApiStatus getProblemWithLongMessage() {
+        ToolingApiStatus.from("", new GradleConnectionException('X' * 70000))
+    }
+
+    private ToolingApiStatus getProblemWithLongStacktrace() {
+        ToolingApiStatus.from("", createException(400))
+    }
+
+    private Throwable createException(int numOfRootCauses) {
+        if (numOfRootCauses == 0) {
+            return new GradleConnectionException("")
+        } else {
+            return new GradleConnectionException("", createException(numOfRootCauses - 1))
+        }
+    }
 }

org.eclipse.buildship.core/src/main/java/org/eclipse/buildship/core/internal/marker/GradleErrorMarker.java

@@ -9,6 +9,8 @@
  ******************************************************************************/
 package org.eclipse.buildship.core.internal.marker;
 
+import java.nio.charset.StandardCharsets;
+
 import com.google.common.base.Throwables;
 
 import org.eclipse.core.resources.IMarker;
@@ -53,16 +55,35 @@ private static void createMarker(int severity, IResource resource, InternalGradl
                 marker.setAttribute(IMarker.LINE_NUMBER, lineNumber);
             }
 
-            marker.setAttribute(IMarker.MESSAGE, message);
+            marker.setAttribute(IMarker.MESSAGE, trimMarkerProperty(message));
             marker.setAttribute(IMarker.PRIORITY, IMarker.PRIORITY_HIGH);
             marker.setAttribute(IMarker.SEVERITY, severity);
             marker.setAttribute(ATTRIBUTE_ROOT_DIR, gradleBuild.getBuildConfig().getRootProjectDirectory().getAbsolutePath());
             if (exception != null) {
                 String stackTrace = Throwables.getStackTraceAsString(exception);
-                marker.setAttribute(GradleErrorMarker.ATTRIBUTE_STACKTRACE, stackTrace);
+                marker.setAttribute(GradleErrorMarker.ATTRIBUTE_STACKTRACE, trimMarkerProperty(stackTrace));
             }
         } catch (CoreException e) {
             CorePlugin.logger().warn("Cannot create Gradle error marker", e);
         }
     }
+
+    /*
+     * The Eclipse platform will throw an exception if a marker property is longer than 65535 bytes
+     * https://github.com/eclipse-platform/eclipse.platform/blob/97d555a8b563dcb3a32bd43ad58ba452fa027a73/resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/MarkerInfo.java#L56-L60
+     */
+    private static String trimMarkerProperty(String property) {
+        // avoid calling String.toBytes() for shorter Strings
+        // UTF-8 can theoretically use up to 4 bytes to represent a code point
+        if (property.length() < 16384) {
+            return property;
+        }
+        // check precise length
+        byte[] bytes = property.getBytes(StandardCharsets.UTF_8);
+        if (bytes.length <= 65535) {
+            return property;
+        }
+        // trim to size if needed
+        return new String(bytes, 0, 65535, StandardCharsets.UTF_8);
+    }
 }