Only consider depth of content types when they are related

resources/tests/org.eclipse.core.tests.resources/plugin.xml

@@ -306,10 +306,25 @@
             file-extensions="conflict2"
             name="Specialized Conflict 2"
             id="sub_conflict2"/>
-      <!-- 
-      	Two unrelated types (sub_conflict3 and unrelated conflict3) are in conflict. 
-      	Order will be arbitrary.
-      	-->
+      <!--
+        A base type and a sub-type (that restates file-spec) are in conflict.
+        Specialized type should be picked if both have describers returning valid
+      -->
+      <content-type
+            file-extensions="conflict2a"
+            name="Conflict 2a"
+            id="base_conflict2a"
+            describer="org.eclipse.core.tests.resources.content.Conflict2aContentDescriber"/>
+      <content-type
+            base-type="base_conflict2a"
+            file-extensions="conflict2a"
+            name="Specialized Conflict 2a"
+            id="sub_conflict2a"
+            describer="org.eclipse.core.tests.resources.content.Conflict2aContentDescriber"/>
+      <!--
+        Two unrelated types (sub_conflict3 and unrelated conflict3) with same priority are in conflict.
+        Order will be arbitrary.
+      -->
       <content-type            		
             id="base_conflict3"                  
             file-extensions="base_conflict3"
@@ -323,6 +338,42 @@
             id="unrelated_conflict3"      
             file-extensions="conflict3"
             name="Unrelated Conflict 3"/>                                              
+      <!--
+        Two unrelated types (sub_conflict4 and unrelated conflict4) with with deeper having higher priority.
+        Order will be by priority.
+      -->
+      <content-type
+            id="base_conflict4"
+            file-extensions="base_conflict4"
+            name="Conflict 4"/>
+      <content-type
+            id="sub_conflict4"
+            base-type="base_conflict4"
+            file-extensions="conflict4"
+            name="Deeper Conflict 4"/>
+      <content-type
+            id="unrelated_conflict4"
+            file-extensions="conflict4"
+            priority="low"
+            name="Unrelated Conflict 4"/>
+      <!--
+        Two unrelated types (sub_conflict5 and unrelated conflict5) with with deeper having lower priority.
+        Order will be by priority.
+      -->
+      <content-type
+            id="base_conflict5"
+            file-extensions="base_conflict5"
+            name="Conflict 5"/>
+      <content-type
+            id="sub_conflict5"
+            base-type="base_conflict5"
+            file-extensions="conflict5"
+            priority="low"
+            name="Deeper Conflict 5"/>
+      <content-type
+            id="unrelated_conflict5"
+            file-extensions="conflict5"
+            name="Unrelated Conflict 5"/>
       <!-- end of conflict-related content types -->
 	  <content-type
             file-extensions="tzt"

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/content/Conflict2aContentDescriber.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2005, 2023 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.core.tests.resources.content;
+
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import org.eclipse.core.runtime.QualifiedName;
+import org.eclipse.core.runtime.content.IContentDescription;
+import org.eclipse.core.runtime.content.ITextContentDescriber;
+
+/**
+ * A content describer that looks for "conflict2a" at the beginning of the
+ * stream as used by
+ * org.eclipse.core.tests.resources.content.IContentTypeManagerTest.testFileSpecConflicts()
+ */
+public class Conflict2aContentDescriber implements ITextContentDescriber {
+
+	@Override
+	public int describe(InputStream contents, IContentDescription description) throws IOException {
+		final byte[] expected = "conflict2a".getBytes(StandardCharsets.UTF_8);
+		byte[] actual = new byte[expected.length];
+		int read = contents.read(actual);
+		if (read == actual.length && Arrays.equals(expected, actual)) {
+			return VALID;
+		}
+		return INVALID;
+	}
+
+	@Override
+	public int describe(Reader contents, IContentDescription description) throws IOException {
+		throw new UnsupportedOperationException("Not used by test");
+	}
+
+	@Override
+	public QualifiedName[] getSupportedOptions() {
+		return IContentDescription.ALL;
+	}
+}

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/content/IContentTypeManagerTest.java

@@ -895,13 +895,33 @@ public void testFileSpecConflicts() throws IOException {
 		IContentType conflict2sub = manager.getContentType(PI_RESOURCES_TESTS + ".sub_conflict2");
 		assertNotNull("2.0", conflict2base);
 		assertNotNull("2.1", conflict2sub);
-		// when submitting contents, for related types, descendant comes first
 
+		// when submitting contents, for related types with indeterminate match, general
+		// comes first
 		IContentType[] selectedConflict2 = manager.findContentTypesFor(getRandomContents(), "test.conflict2");
 		assertEquals("2.2", 2, selectedConflict2.length);
 		assertEquals("2.3", selectedConflict2[0], conflict2base);
 		assertEquals("2.4", selectedConflict2[1], conflict2sub);
 
+		IContentType conflict2abase = manager.getContentType(PI_RESOURCES_TESTS + ".base_conflict2a");
+		IContentType conflict2asub = manager.getContentType(PI_RESOURCES_TESTS + ".sub_conflict2a");
+		assertNotNull("2.5", conflict2abase);
+		assertNotNull("2.6", conflict2asub);
+
+		// when submitting contents, for related types with valid match, specific
+		// comes first
+		IContentType[] selectedConflict2a = manager
+				.findContentTypesFor(getInputStream("conflict2a", StandardCharsets.UTF_8), "test.conflict2a");
+		assertEquals("2.7", 2, selectedConflict2a.length);
+		assertEquals("2.8", selectedConflict2a[0], conflict2asub);
+		assertEquals("2.9", selectedConflict2a[1], conflict2abase);
+
+		// when not submitting contents, for related types, most general type prevails
+		selectedConflict2a = manager.findContentTypesFor("test.conflict2a");
+		assertEquals("2.10", 2, selectedConflict2a.length);
+		assertEquals("2.11", selectedConflict2a[0], conflict2abase);
+		assertEquals("2.12", selectedConflict2a[1], conflict2asub);
+
 		IContentType conflict3base = manager.getContentType(PI_RESOURCES_TESTS + ".base_conflict3");
 		IContentType conflict3sub = manager.getContentType(PI_RESOURCES_TESTS + ".sub_conflict3");
 		IContentType conflict3unrelated = manager.getContentType(PI_RESOURCES_TESTS + ".unrelated_conflict3");
@@ -910,13 +930,44 @@ public void testFileSpecConflicts() throws IOException {
 		assertNotNull("3.0.3", conflict3unrelated);
 
 		// Two unrelated types (sub_conflict3 and unrelated conflict3) are in conflict.
-		// Order will be based on depth (more general first since they don't have
-		// describers)
+		// Order will be arbitrary (lexicographically).
 
 		IContentType[] selectedConflict3 = manager.findContentTypesFor(getRandomContents(), "test.conflict3");
 		assertEquals("4.0", 2, selectedConflict3.length);
-		assertEquals("4.1", selectedConflict3[0], conflict3unrelated);
-		assertEquals("4.2", selectedConflict3[1], conflict3sub);
+		assertEquals("4.1", selectedConflict3[0], conflict3sub);
+		assertEquals("4.2", selectedConflict3[1], conflict3unrelated);
+
+		IContentType conflict4base = manager.getContentType(PI_RESOURCES_TESTS + ".base_conflict4");
+		IContentType conflict4sub = manager.getContentType(PI_RESOURCES_TESTS + ".sub_conflict4");
+		IContentType conflict4unrelated_lowPriority = manager.getContentType(PI_RESOURCES_TESTS + ".unrelated_conflict4");
+		assertNotNull("5.0.1", conflict4base);
+		assertNotNull("5.0.2", conflict4sub);
+		assertNotNull("5.0.4", conflict4unrelated_lowPriority);
+
+		// Two unrelated types (sub_conflict4 and unrelated conflict4) are in conflict,
+		// but with different priorities
+		// Order will be based on priority
+
+		IContentType[] selectedConflict4 = manager.findContentTypesFor(getRandomContents(), "test.conflict4");
+		assertEquals("6.0", 2, selectedConflict4.length);
+		assertEquals("6.1", selectedConflict4[0], conflict4sub);
+		assertEquals("6.2", selectedConflict4[1], conflict4unrelated_lowPriority);
+
+		IContentType conflict5base = manager.getContentType(PI_RESOURCES_TESTS + ".base_conflict5");
+		IContentType conflict5sub_lowPriority = manager.getContentType(PI_RESOURCES_TESTS + ".sub_conflict5");
+		IContentType conflict5unrelated = manager.getContentType(PI_RESOURCES_TESTS + ".unrelated_conflict5");
+		assertNotNull("6.0.1", conflict5base);
+		assertNotNull("6.0.2", conflict5sub_lowPriority);
+		assertNotNull("6.0.5", conflict5unrelated);
+
+		// Two unrelated types (sub_conflict5 and unrelated conflict5) are in conflict,
+		// but with different priorities
+		// Order will be based on priority
+
+		IContentType[] selectedConflict5 = manager.findContentTypesFor(getRandomContents(), "test.conflict5");
+		assertEquals("7.0", 2, selectedConflict5.length);
+		assertEquals("7.1", selectedConflict5[0], conflict5unrelated);
+		assertEquals("7.2", selectedConflict5[1], conflict5sub_lowPriority);
 	}
 
 	@Test

runtime/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/internal/content/ContentTypeCatalog.java

@@ -41,16 +41,30 @@ public final class ContentTypeCatalog {
 	private ContentTypeManager manager;
 
 	/**
-	 * A sorting policy where the more generic content type wins. Lexicographical comparison is done
-	 * as a last resort when all other criteria fail.
+	 * Return true if type1 is an ancestor of type2 or if type2 is an ancestor of
+	 * type1
+	 *
+	 * @param type1
+	 * @param type2
+	 * @return true type1 is ancestor or type2, or vice versa. false otherwise
+	 */
+	private static boolean isAncestor(ContentType type1, ContentType type2) {
+		return type1.isKindOf(type2) || type2.isKindOf(type1);
+	}
+
+	/**
+	 * A sorting policy where the more generic content type wins. Lexicographical
+	 * comparison is done as a last resort when all other criteria fail.
 	 */
 	private final Comparator<IContentType> policyConstantGeneralIsBetter = (IContentType o1, IContentType o2) -> {
 		ContentType type1 = (ContentType) o1;
 		ContentType type2 = (ContentType) o2;
-		// first criteria: depth - the lower, the better
-		int depthCriteria = type1.getDepth() - type2.getDepth();
-		if (depthCriteria != 0)
-			return depthCriteria;
+		if (isAncestor(type1, type2)) {
+			// first criteria: depth - the lower, the better
+			int depthCriteria = type1.getDepth() - type2.getDepth();
+			if (depthCriteria != 0)
+				return depthCriteria;
+		}
 		// second criteria: priority - the higher, the better
 		int priorityCriteria = type1.getPriority() - type2.getPriority();
 		if (priorityCriteria != 0)
@@ -66,10 +80,12 @@ public final class ContentTypeCatalog {
 	private Comparator<IContentType> policyConstantSpecificIsBetter = (IContentType o1, IContentType o2) -> {
 		ContentType type1 = (ContentType) o1;
 		ContentType type2 = (ContentType) o2;
-		// first criteria: depth - the higher, the better
-		int depthCriteria = type1.getDepth() - type2.getDepth();
-		if (depthCriteria != 0)
-			return -depthCriteria;
+		if (isAncestor(type1, type2)) {
+			// first criteria: depth - the higher, the better
+			int depthCriteria = type1.getDepth() - type2.getDepth();
+			if (depthCriteria != 0)
+				return -depthCriteria;
+		}
 		// second criteria: priority - the higher, the better
 		int priorityCriteria = type1.getPriority() - type2.getPriority();
 		if (priorityCriteria != 0)
@@ -84,10 +100,12 @@ public final class ContentTypeCatalog {
 	private Comparator<IContentType> policyGeneralIsBetter = (IContentType o1, IContentType o2) -> {
 		ContentType type1 = (ContentType) o1;
 		ContentType type2 = (ContentType) o2;
-		// first criteria: depth - the lower, the better
-		int depthCriteria = type1.getDepth() - type2.getDepth();
-		if (depthCriteria != 0)
-			return depthCriteria;
+		if (isAncestor(type1, type2)) {
+			// first criteria: depth - the lower, the better
+			int depthCriteria = type1.getDepth() - type2.getDepth();
+			if (depthCriteria != 0)
+				return depthCriteria;
+		}
 		// second criteria: priority - the higher, the better
 		int priorityCriteria = type1.getPriority() - type2.getPriority();
 		if (priorityCriteria != 0)
@@ -109,10 +127,12 @@ public final class ContentTypeCatalog {
 	private Comparator<IContentType> policySpecificIsBetter = (IContentType o1, IContentType o2) -> {
 		ContentType type1 = (ContentType) o1;
 		ContentType type2 = (ContentType) o2;
-		// first criteria: depth - the higher, the better
-		int depthCriteria = type1.getDepth() - type2.getDepth();
-		if (depthCriteria != 0)
-			return -depthCriteria;
+		if (isAncestor(type1, type2)) {
+			// first criteria: depth - the higher, the better
+			int depthCriteria = type1.getDepth() - type2.getDepth();
+			if (depthCriteria != 0)
+				return -depthCriteria;
+		}
 		// second criteria: priority - the higher, the better
 		int priorityCriteria = type1.getPriority() - type2.getPriority();
 		if (priorityCriteria != 0)