Support empty lower and upper bounds in P2 VersionRange

This enables support for version range specifications where the lower or
upper bound is not specified and the delimiting bracket is directly next
to the separating colon. For example '[1,)' or '(,1]' but also '(,)' can
then be parsed successfully.

The type of supported brackets for an empty or unspecified bound is
something that's not inherently obvious. From a mathematical perspective
an empty bound can be considered equivalent to infinity. And in math may
not say inclusive infinity. From that perspective only '[1,infinity)'
respectively '[1,)' would be permitted, but not '[1,]'.
But technically infinity has a specific value for P2 versions, i.e.
Version.MAX_VERSION. So if one really wants to cover all possible
values, the upper bound still has to be inclusive, i.e. ']'. For the
lower bound the situation is similar, where '0.0.0' or the
'empty'-version is the smallest one possible.

bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/metadata/VersionRange.java

@@ -157,11 +157,11 @@ public VersionRange(String versionRange) {
 		} else {
 			fmt = VersionFormat.OSGI_FORMAT;
 		}
-		String minStr;
-		String maxStr;
+		final String minStr;
+		final String maxStr;
 		StringBuilder sb = new StringBuilder();
 		if (c == '[' || c == '(') {
-			includeMin = (c == '[');
+			boolean isClosedBound = c == '[';
 			pos = copyEscaped(versionRange, ++pos, ",)]", sb); //$NON-NLS-1$
 			if (pos >= top) {
 				throw new IllegalArgumentException(NLS.bind(Messages.premature_EOS_0, versionRange));
@@ -171,6 +171,7 @@ public VersionRange(String versionRange) {
 				throw new IllegalArgumentException(NLS.bind(Messages.missing_comma_in_range_0, versionRange));
 			}
 			minStr = sb.toString();
+			includeMin = isClosedBound || minStr.isEmpty();
 			sb.setLength(0);
 			pos = copyEscaped(versionRange, pos, ")]", sb); //$NON-NLS-1$
 			if (pos >= top) {
@@ -179,7 +180,7 @@ public VersionRange(String versionRange) {
 			maxStr = sb.toString();
 
 			c = versionRange.charAt(pos++);
-			includeMax = (c == ']');
+			includeMax = c == ']' || maxStr.isEmpty();
 		} else {
 			StringBuilder sbMin = new StringBuilder();
 			pos = copyEscaped(versionRange, pos, rawPrefix ? "/" : null, sbMin); //$NON-NLS-1$
@@ -248,9 +249,11 @@ public VersionRange(String versionRange) {
 					}
 				}
 			}
-			minVersion = VersionFormat.parseRaw(minStr, fmt, origMin);
+			minVersion = minStr.isEmpty() ? Version.emptyVersion : VersionFormat.parseRaw(minStr, fmt, origMin);
 			if (maxStr != null) {
-				if (maxStr.equals(minStr)) {
+				if (maxStr.isEmpty()) {
+					maxVersion = Version.MAX_VERSION;
+				} else if (maxStr.equals(minStr)) {
 					maxVersion = minVersion;
 				} else {
 					maxVersion = VersionFormat.parseRaw(maxStr, fmt, origMax);
@@ -262,9 +265,11 @@ public VersionRange(String versionRange) {
 			if (fmt == null) {
 				fmt = VersionFormat.OSGI_FORMAT;
 			}
-			minVersion = fmt.parse(minStr);
+			minVersion = minStr.isEmpty() ? Version.emptyVersion : fmt.parse(minStr);
 			if (maxStr != null) {
-				if (maxStr.equals(minStr)) {
+				if (maxStr.isEmpty()) {
+					maxVersion = Version.MAX_VERSION;
+				} else if (maxStr.equals(minStr)) {
 					maxVersion = minVersion;
 				} else {
 					maxVersion = fmt.parse(maxStr);

bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/omniVersion/OSGiRangeTest.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2010 Cloudsmith Inc. and others.
+ * Copyright (c) 2009, 2024 Cloudsmith Inc. and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -27,6 +27,10 @@
  * Tests ranges of versions specified with osgi (default) version format.
  */
 public class OSGiRangeTest extends VersionTesting {
+
+	private static Version ONE = Version.parseVersion("1");
+	private static Version TWO = Version.parseVersion("2");
+
 	@Test
 	public void testSingleVersionRange() {
 		VersionRange range;
@@ -100,6 +104,35 @@ public void testRangeStrings() {
 		assertEquals("(1.0.0.abcdef,2.0.0.abcdef)", v.toString());
 	}
 
+	@Test
+	public void testEmptyRange() {
+		assertBounds("", true, Version.emptyVersion, Version.MAX_VERSION, true);
+	}
+
+	@Test
+	public void testExplicitLowerAndUpperBound() {
+		assertBounds("[1,2)", true, ONE, TWO, false);
+		assertBounds("[1,2]", true, ONE, TWO, true);
+	}
+
+	@Test
+	public void testNoLowerBound() {
+		assertBounds("(,1)", true, Version.emptyVersion, ONE, false);
+		assertBounds("[,1)", true, Version.emptyVersion, ONE, false);
+	}
+
+	@Test
+	public void testNoUpperBound() {
+		assertBounds("[1,)", true, ONE, Version.MAX_VERSION, true);
+		assertBounds("[1,]", true, ONE, Version.MAX_VERSION, true);
+	}
+
+	@Test
+	public void testNoLowerAndUpperBound() {
+		assertBounds("(,)", true, Version.emptyVersion, Version.MAX_VERSION, true);
+		assertBounds("[,]", true, Version.emptyVersion, Version.MAX_VERSION, true);
+	}
+
 	/**
 	 * Tests that null values passed to the {@link VersionRange} constructor are not
 	 * interpreted as MIN/MAX versions.

bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/omniVersion/RawRangeTest.java

@@ -25,6 +25,10 @@
  * Tests version ranges specified using raw.
  */
 public class RawRangeTest extends VersionTesting {
+
+	private static Version ONE = Version.parseVersion("raw:1");
+	private static Version TWO = Version.parseVersion("raw:2");
+
 	@Test
 	public void testEmptyRange() {
 		VersionRange range = new VersionRange("raw:''");
@@ -112,6 +116,30 @@ public void testLowerThan() {
 		assertNotIncludedInRange("1.5", upperBound, "raw:2.1");
 	}
 
+	@Test
+	public void testExplicitLowerAndUpperBound() {
+		assertBounds("raw:[1,2)", true, ONE, TWO, false);
+		assertBounds("raw:[1,2]", true, ONE, TWO, true);
+	}
+
+	@Test
+	public void testNoLowerBound() {
+		assertBounds("raw:(,1)", true, Version.emptyVersion, ONE, false);
+		assertBounds("raw:[,1)", true, Version.emptyVersion, ONE, false);
+	}
+
+	@Test
+	public void testNoUpperBound() {
+		assertBounds("raw:[1,)", true, ONE, Version.MAX_VERSION, true);
+		assertBounds("raw:[1,]", true, ONE, Version.MAX_VERSION, true);
+	}
+
+	@Test
+	public void testNoLowerAndUpperBound() {
+		assertBounds("raw:(,)", true, Version.emptyVersion, Version.MAX_VERSION, true);
+		assertBounds("raw:[,]", true, Version.emptyVersion, Version.MAX_VERSION, true);
+	}
+
 	@Test
 	public void testSerialize() {
 		VersionRange v = null;

bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/omniVersion/VersionTesting.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2017 Cloudsmith Inc. and others.
+ * Copyright (c) 2009, 2024 Cloudsmith Inc. and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -33,6 +33,7 @@
  * Base class for version testing. Adds useful assert methods.
  */
 public class VersionTesting {
+
 	/**
 	 * Asserts that the versionString version is included in the range.
 	 */
@@ -47,6 +48,15 @@ public void assertNotIncludedInRange(String message, VersionRange range, String
 		assertFalse(message, range.isIncluded(Version.parseVersion(versionString)));
 	}
 
+	public void assertBounds(String rangeSpecification, boolean includeMin, Version lowerBound, Version upperBound,
+			boolean includeMax) {
+		VersionRange range = new VersionRange(rangeSpecification);
+		assertEquals(includeMin, range.getIncludeMinimum());
+		assertEquals(includeMax, range.getIncludeMaximum());
+		assertEquals(lowerBound, range.getMinimum());
+		assertEquals(upperBound, range.getMaximum());
+	}
+
 	/**
 	 * A strict assertion of order. asserts that b > a, a < b, a !=b, b != a
 	 */