DirCacheEditor: Apply PathEdit for each stage

This behavior was defined in the Javadoc of PathEdit, but not actually
implemented.

It's necessary when one wants to use a PathEdit to check out a specific
stage in apply.

Bug: 390147
Change-Id: Iaed5cf60c554fc17e6c4d188caf4f0231da920d0
Signed-off-by: Chris Aniszczyk <zx@twitter.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/dircache/DirCachePathEditTest.java

@@ -44,6 +44,9 @@ package org.eclipse.jgit.dircache;
 
 import static org.junit.Assert.assertEquals;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
@@ -66,6 +69,19 @@ public class DirCachePathEditTest {
 
 	}
 
+	private static final class RecordingEdit extends PathEdit {
+		final List<DirCacheEntry> entries = new ArrayList<DirCacheEntry>();
+
+		public RecordingEdit(String entryPath) {
+			super(entryPath);
+		}
+
+		@Override
+		public void apply(DirCacheEntry ent) {
+			entries.add(ent);
+		}
+	}
+
 	@Test
 	public void testAddDeletePathAndTreeNormalNames() {
 		DirCache dc = DirCache.newInCore();
@@ -114,4 +130,31 @@ public class DirCachePathEditTest {
 		assertEquals("a.", dc.getEntry(0).getPathString());
 		assertEquals("ab", dc.getEntry(1).getPathString());
 	}
+
+	@Test
+	public void testPathEditShouldBeCalledForEachStage() throws Exception {
+		DirCache dc = DirCache.newInCore();
+		DirCacheBuilder builder = new DirCacheBuilder(dc, 3);
+		builder.add(createEntry("a", DirCacheEntry.STAGE_1));
+		builder.add(createEntry("a", DirCacheEntry.STAGE_2));
+		builder.add(createEntry("a", DirCacheEntry.STAGE_3));
+		builder.finish();
+
+		DirCacheEditor editor = dc.editor();
+		RecordingEdit recorder = new RecordingEdit("a");
+		editor.add(recorder);
+		editor.finish();
+
+		List<DirCacheEntry> entries = recorder.entries;
+		assertEquals(3, entries.size());
+		assertEquals(DirCacheEntry.STAGE_1, entries.get(0).getStage());
+		assertEquals(DirCacheEntry.STAGE_2, entries.get(1).getStage());
+		assertEquals(DirCacheEntry.STAGE_3, entries.get(2).getStage());
+	}
+
+	private static DirCacheEntry createEntry(String path, int stage) {
+		DirCacheEntry entry = new DirCacheEntry(path, stage);
+		entry.setFileMode(FileMode.REGULAR_FILE);
+		return entry;
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheEditor.java

@@ -146,19 +146,22 @@ public class DirCacheEditor extends BaseDirCacheEditor {
 				continue;
 			}
 
-			final DirCacheEntry ent;
 			if (missing) {
-				ent = new DirCacheEntry(e.path);
+				final DirCacheEntry ent = new DirCacheEntry(e.path);
 				e.apply(ent);
 				if (ent.getRawMode() == 0)
 					throw new IllegalArgumentException(MessageFormat.format(JGitText.get().fileModeNotSetForPath
 							, ent.getPathString()));
+				fastAdd(ent);
 			} else {
-				ent = cache.getEntry(eIdx);
+				// Apply to all entries of the current path (different stages)
+				for (int i = eIdx; i < lastIdx; i++) {
+					final DirCacheEntry ent = cache.getEntry(i);
 					e.apply(ent);
-			}
 					fastAdd(ent);
 				}
+			}
+		}
 
 		final int cnt = maxIdx - lastIdx;
 		if (cnt > 0)