Suggest a micro change for default added interface methods and fields

If one adds a field to an interface or a default method this will not
result in any problem for the consumer or the provider of the interface.

Because of this these changes can be made in a micro package version
increment.

Author: laeubi

apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/builder/BaseApiAnalyzer.java

@@ -2307,14 +2307,41 @@ private void checkApiComponentPackageVersions(BundleComponent referenceBundle, B
 				.collect(Collectors.toMap(ExportPackageDescription::getName, Function.identity()));
 		// a mapping between a package name and a required change
 		Map<String, RequiredPackageVersionChange> requiredChanges = new HashMap<>();
+		Set<IDelta> microChanged = new HashSet<>();
+		// here we check for problems that are actually only a micro change in package
+		// version in the compatible category
+		for (IDelta delta : compatibleChanges) {
+			if (isMicroPackageChange(delta)) {
+				microChanged.add(delta);
+				analyzePackageDelta(delta, IApiProblem.MICRO_VERSION_CHANGE_PACKAGE, referencePackages,
+						componentPackages, requiredChanges);
+			}
+		}
+		// here we check for problems that are actually only a micro change in package
+		// version in the compatible category
+		for (IDelta delta : breakingChanges) {
+			if (isMicroPackageChange(delta)) {
+				microChanged.add(delta);
+				analyzePackageDelta(delta, IApiProblem.MICRO_VERSION_CHANGE_PACKAGE, referencePackages,
+						componentPackages, requiredChanges);
+			}
+		}
 		// we must compare compatible changes first, so these where overwritten later by
 		// breaking changes probably
 		for (IDelta delta : compatibleChanges) {
+			if (microChanged.contains(delta)) {
+				// we have already identified the delta as a micro change
+				continue;
+			}
 			// a compatible change must result in a minor package version increment
 			analyzePackageDelta(delta, IApiProblem.MINOR_VERSION_CHANGE_PACKAGE, referencePackages, componentPackages,
 					requiredChanges);
 		}
 		for (IDelta delta : breakingChanges) {
+			if (microChanged.contains(delta)) {
+				// we have already identified the delta as a micro change
+				continue;
+			}
 			// a breaking change must result in a major package change
 			analyzePackageDelta(delta, IApiProblem.MAJOR_VERSION_CHANGE_PACKAGE, referencePackages, componentPackages,
 					requiredChanges);
@@ -2330,6 +2357,25 @@ private void checkApiComponentPackageVersions(BundleComponent referenceBundle, B
 		}
 	}
 
+	private boolean isMicroPackageChange(IDelta delta) {
+		if (delta.getElementType() == IDelta.INTERFACE_ELEMENT_TYPE) {
+			// for interface types we can have some changes that are actually compatible
+			// even with provider version range
+			if (delta.getKind() == IDelta.ADDED) {
+				if (delta.getFlags() == IDelta.DEFAULT_METHOD) {
+					// adding a default method to an interface is not required to change the
+					// implementation
+					return true;
+				}
+				if (delta.getFlags() == IDelta.FIELD) {
+					// adding a field does not harm neither consumer nor providers
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
 	private void analyzePackageDelta(IDelta delta, int category,
 			Map<String, ExportPackageDescription> referencePackages,
 			Map<String, ExportPackageDescription> componentPackages,
@@ -2353,7 +2399,10 @@ private void analyzePackageDelta(IDelta delta, int category,
 				return;
 			}
 			Version suggested;
-			if (IApiProblem.MINOR_VERSION_CHANGE_PACKAGE == category) {
+			if (IApiProblem.MICRO_VERSION_CHANGE_PACKAGE == category) {
+				suggested = new Version(baselineVersion.getMajor(), baselineVersion.getMinor(),
+						baselineVersion.getMicro() + 1);
+			} else if (IApiProblem.MINOR_VERSION_CHANGE_PACKAGE == category) {
 				suggested = new Version(baselineVersion.getMajor(), baselineVersion.getMinor() + 1, 0);
 			} else {
 				suggested = new Version(baselineVersion.getMajor() + 1, baselineVersion.getMinor(), 0);
@@ -2366,11 +2415,17 @@ private void analyzePackageDelta(IDelta delta, int category,
 			if (compVersion.getMajor() > baselineVersion.getMajor()) {
 				return;
 			}
-			if (IApiProblem.MINOR_VERSION_CHANGE_PACKAGE == category) {
+			if (IApiProblem.MINOR_VERSION_CHANGE_PACKAGE == category
+					|| IApiProblem.MICRO_VERSION_CHANGE_PACKAGE == category) {
 				if (compVersion.getMinor() > baselineVersion.getMinor()) {
 					return;
 				}
 			}
+			if (IApiProblem.MICRO_VERSION_CHANGE_PACKAGE == category) {
+				if (compVersion.getMicro() > baselineVersion.getMicro()) {
+					return;
+				}
+			}
 			requiredChanges.put(packageName,
 					new RequiredPackageVersionChange(category, baselineVersion, compVersion, suggested));
 		}

apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/problems/ApiProblemFactory.java

@@ -594,6 +594,8 @@ public static int getProblemMessageId(int category, int element, int kind, int f
 						return 65;
 					case IApiProblem.MINOR_VERSION_CHANGE_PACKAGE:
 						return 63;
+					case IApiProblem.MICRO_VERSION_CHANGE_PACKAGE:
+						return 68;
 					default:
 						break;
 				}

apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/problems/problemmessages.properties

@@ -11,7 +11,7 @@
 # Contributors:
 #     IBM Corporation - initial API and implementation
 ###############################################################################
-# available message ids  68, 70, 71, 75, 80,
+# available message ids  70, 71, 75, 80,
 # 82, 83, 88, 90, 93
 
 #API baseline 
@@ -39,6 +39,7 @@
 62 = The major version should be incremented in version {0}, because the bundle {1} is no longer re-exported
 63 = The minor version for the package ''{0}'' should be incremented to version {1}, since new APIs have been added since version {2}
 65 = The major version for the package ''{0}'' should be incremented to version {1}, since API breakage occurred since version {2}
+68 = The micro version for the package ''{0}'' should be incremented to version {1}, since API changes occurred since version {2}
 
 #API usage problems
 #{0} = referenced type name

apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/provisional/problems/IApiProblem.java

@@ -262,6 +262,16 @@ public interface IApiProblem {
 	 */
 	public static final int MINOR_VERSION_CHANGE_PACKAGE = 12;
 
+	/**
+	 * Constant representing the value of the micro version change
+	 * {@link IApiProblem} kind for a package. <br>
+	 * Value is: <code>13</code>
+	 *
+	 * @see #getKind()
+	 * @see #CATEGORY_VERSION
+	 */
+	public static final int MICRO_VERSION_CHANGE_PACKAGE = 13;
+
 	public static final int ILLEGAL_EXTEND = 1;
 
 	/**