Bug 550471 - Improve compatibility of new TextUtilities.indexOfI20190912-1800

Old implementation allowed negative offsets then the improved variant
must also.

Change-Id: Idf732397d62419690f3f870e590178b3ff0bcbbd
Signed-off-by: Paul Pazderski <paul-eclipse@ppazderski.de>

2 files changed, 28 insertions, 4 deletions

diff --git a/org.eclipse.text.tests/src/org/eclipse/text/tests/TextUtilitiesTest.java b/org.eclipse.text.tests/src/org/eclipse/text/tests/TextUtilitiesTest.java
index cdec2582a2e..1292ecf3d18 100644
--- a/org.eclipse.text.tests/src/org/eclipse/text/tests/TextUtilitiesTest.java
+++ b/org.eclipse.text.tests/src/org/eclipse/text/tests/TextUtilitiesTest.java
@@ -281,6 +281,10 @@ public class TextUtilitiesTest {
 	@SuppressWarnings("deprecation")
 	public void testIndexOf() {
 		int[] result;
+		result = TextUtilities.indexOf(new String[0], "xxxxxxxxxx", 0);
+		assertEquals(-1, result[0]);
+		assertEquals(-1, result[1]);
+
 		result = TextUtilities.indexOf(new String[] { "a", "ab", "abc" }, "xxxxxxxxxx", 0);
 		assertEquals(-1, result[0]);
 		assertEquals(-1, result[1]);
@@ -311,6 +315,14 @@ public class TextUtilitiesTest {
 		assertEquals(0, result[0]);
 		assertEquals(0, result[1]);
 
+		result = TextUtilities.indexOf(new String[] { "abc" }, "foobarabcd", -5);
+		assertEquals(6, result[0]);
+		assertEquals(0, result[1]);
+
+		result = TextUtilities.indexOf(new String[] { "abc" }, "foobarabcd", 20);
+		assertEquals(-1, result[0]);
+		assertEquals(-1, result[1]);
+
 		try {
 			TextUtilities.indexOf(null, "foobarabcd", 0);
 			fail("Exception not thrown");
@@ -324,6 +336,13 @@ public class TextUtilitiesTest {
 		} catch (NullPointerException ex) {
 			// expected
 		}
+
+		try {
+			TextUtilities.indexOf(new String[] { "abc" }, null, 0);
+			fail("Exception not thrown");
+		} catch (NullPointerException ex) {
+			// expected
+		}
 	}
 
 	@Test
diff --git a/org.eclipse.text/src/org/eclipse/jface/text/TextUtilities.java b/org.eclipse.text/src/org/eclipse/jface/text/TextUtilities.java
index 733c831cb00..29e1b3e0578 100644
--- a/org.eclipse.text/src/org/eclipse/jface/text/TextUtilities.java
+++ b/org.eclipse.text/src/org/eclipse/jface/text/TextUtilities.java
@@ -81,10 +81,12 @@ public class TextUtilities {
 	 * @deprecated use {@link MultiStringMatcher#indexOf(CharSequence, int, String...)} instead.
 	 *             Notable differences:
 	 *             <ul>
-	 *             <li>new indexOf will tolerate <code>null</code> and empty search strings (old
-	 *             accepted empty but throw on <code>null</code>)</li>
-	 *             <li>new indexOf will <b>not</b> match empty string (old matched empty if nothing
-	 *             else matched)</li>
+	 *             <li>new matcher indexOf does not allow negative offsets (old matcher treated them
+	 *             as <code>0</code>)</li>
+	 *             <li>new matcher indexOf will tolerate <code>null</code> and empty search strings
+	 *             (old accepted empty but throw on <code>null</code>)</li>
+	 *             <li>new matcher indexOf will <b>not</b> match empty string (old matched empty if
+	 *             nothing else matched)</li>
 	 *             </ul>
 	 *             For the common case of searching the next default {@link #DELIMITERS delimiter}
 	 *             use the optimized {@link #nextDelimiter(CharSequence, int)} method instead.
@@ -98,6 +100,9 @@ public class TextUtilities {
 		for (String searchString : searchStrings) {
 			Objects.requireNonNull(searchString);
 		}
+		if (offset < 0) {
+			offset = 0; // for compatibility with old implementation
+		}
 		final MultiStringMatcher.Match match= MultiStringMatcher.indexOf(text, offset, searchStrings);
 		if (match != null) {
 			for (int i= 0; i < searchStrings.length; i++) {