Teach ResolveMerger to create more correct DirCacheEntry's

Currently, after a merge/cherry-pick/rebase, all index entries are
smudged as the ResolveMerger never sets entry lengths and/or
modification times. This change teaches it to re-set them at least for
things it did not touch. The other entries are then repaired when the
index is persisted, or entries are checked out.

Change-Id: I0944f2017483d32043d0d09409b13055b5609a4b
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

1 files changed, 74 insertions, 26 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java b/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java
index 2410d6fe04..3034bfb5d3 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java
@@ -204,6 +204,13 @@ public class ResolveMerger extends ThreeWayMerger {
 			}
 
 			if (!inCore) {
+				// No problem found. The only thing left to be done is to
+				// checkout
+				// all files from "theirs" which have been selected to go into
+				// the
+				// new index.
+				checkout();
+
 				// All content-merges are successfully done. If we can now write the
 				// new index we are on quite safe ground. Even if the checkout of
 				// files coming from "theirs" fails the user can work around such
@@ -214,10 +221,6 @@ public class ResolveMerger extends ThreeWayMerger {
 				}
 				builder = null;
 
-				// No problem found. The only thing left to be done is to checkout
-				// all files from "theirs" which have been selected to go into the
-				// new index.
-				checkout();
 			} else {
 				builder.finish();
 				builder = null;
@@ -313,13 +316,18 @@ public class ResolveMerger extends ThreeWayMerger {
 	 * @param path
 	 * @param p
 	 * @param stage
+	 * @param lastMod
+	 * @param len
 	 * @return the entry which was added to the index
 	 */
-	private DirCacheEntry add(byte[] path, CanonicalTreeParser p, int stage) {
+	private DirCacheEntry add(byte[] path, CanonicalTreeParser p, int stage,
+			long lastMod, long len) {
 		if (p != null && !p.getEntryFileMode().equals(FileMode.TREE)) {
 			DirCacheEntry e = new DirCacheEntry(path, stage);
 			e.setFileMode(p.getEntryFileMode());
 			e.setObjectId(p.getEntryObjectId());
+			e.setLastModified(lastMod);
+			e.setLength(len);
 			builder.add(e);
 			return e;
 		}
@@ -327,6 +335,25 @@ public class ResolveMerger extends ThreeWayMerger {
 	}
 
 	/**
+	 * adds a entry to the index builder which is a copy of the specified
+	 * DirCacheEntry
+	 *
+	 * @param e
+	 *            the entry which should be copied
+	 *
+	 * @return the entry which was added to the index
+	 */
+	private DirCacheEntry keep(DirCacheEntry e) {
+		DirCacheEntry newEntry = new DirCacheEntry(e.getPathString(), e.getStage());
+			newEntry.setFileMode(e.getFileMode());
+		newEntry.setObjectId(e.getObjectId());
+		newEntry.setLastModified(e.getLastModified());
+		newEntry.setLength(e.getLength());
+		builder.add(newEntry);
+		return newEntry;
+	}
+
+	/**
 	 * Processes one path and tries to merge. This method will do all do all
 	 * trivial (not content) merges and will also detect if a merge will fail.
 	 * The merge will fail when one of the following is true
@@ -382,12 +409,27 @@ public class ResolveMerger extends ThreeWayMerger {
 		if (isIndexDirty())
 			return false;
 
+		DirCacheEntry ourDce = null;
+
+		if (index == null) {
+			// create a fake DCE, but only if ours is valid. ours is kept only
+			// in case it is valid, so a null ourDce is ok in all other cases.
+			if (modeO != 0) {
+				ourDce = new DirCacheEntry(tw.getRawPath());
+				ourDce.setObjectId(tw.getObjectId(T_OURS));
+				ourDce.setFileMode(tw.getFileMode(T_OURS));
+			}
+		} else {
+			ourDce = index.getDirCacheEntry();
+		}
+
 		if (nonTree(modeO) && nonTree(modeT) && tw.idEqual(T_OURS, T_THEIRS)) {
 			// OURS and THEIRS have equal content. Check the file mode
 			if (modeO == modeT) {
 				// content and mode of OURS and THEIRS are equal: it doesn't
-				// matter which one we choose. OURS is chosen.
-				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_0);
+				// matter which one we choose. OURS is chosen. Since the index
+				// is clean (the index matches already OURS) we can keep the existing one
+				keep(ourDce);
 				// no checkout needed!
 				return true;
 			} else {
@@ -398,22 +440,25 @@ public class ResolveMerger extends ThreeWayMerger {
 				if (newMode != FileMode.MISSING.getBits()) {
 					if (newMode == modeO)
 						// ours version is preferred
-						add(tw.getRawPath(), ours, DirCacheEntry.STAGE_0);
+						keep(ourDce);
 					else {
 						// the preferred version THEIRS has a different mode
 						// than ours. Check it out!
 						if (isWorktreeDirty(work))
 							return false;
+						// we know about length and lastMod only after we have written the new content.
+						// This will happen later. Set these values to 0 for know.
 						DirCacheEntry e = add(tw.getRawPath(), theirs,
-								DirCacheEntry.STAGE_0);
+								DirCacheEntry.STAGE_0, 0, 0);
 						toBeCheckedOut.put(tw.getPathString(), e);
 					}
 					return true;
 				} else {
-					// FileModes are not mergeable. We found a conflict on modes
-					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1);
-					add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2);
-					add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3);
+					// FileModes are not mergeable. We found a conflict on modes.
+					// For conflicting entries we don't know lastModified and length.
+					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
+					add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
+					add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
 					unmergedPaths.add(tw.getPathString());
 					mergeResults.put(
 							tw.getPathString(),
@@ -426,8 +471,8 @@ public class ResolveMerger extends ThreeWayMerger {
 
 		if (nonTree(modeO) && modeB == modeT && tw.idEqual(T_BASE, T_THEIRS)) {
 			// THEIRS was not changed compared to BASE. All changes must be in
-			// OURS. OURS is chosen.
-			add(tw.getRawPath(), ours, DirCacheEntry.STAGE_0);
+			// OURS. OURS is chosen. We can keep the existing entry.
+			keep(ourDce);
 			// no checkout needed!
 			return true;
 		}
@@ -440,8 +485,11 @@ public class ResolveMerger extends ThreeWayMerger {
 			if (isWorktreeDirty(work))
 				return false;
 			if (nonTree(modeT)) {
+				// we know about length and lastMod only after we have written
+				// the new content.
+				// This will happen later. Set these values to 0 for know.
 				DirCacheEntry e = add(tw.getRawPath(), theirs,
-						DirCacheEntry.STAGE_0);
+						DirCacheEntry.STAGE_0, 0, 0);
 				if (e != null)
 					toBeCheckedOut.put(tw.getPathString(), e);
 				return true;
@@ -460,16 +508,16 @@ public class ResolveMerger extends ThreeWayMerger {
 			// detected later
 			if (nonTree(modeO) && !nonTree(modeT)) {
 				if (nonTree(modeB))
-					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1);
-				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2);
+					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
+				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
 				unmergedPaths.add(tw.getPathString());
 				enterSubtree = false;
 				return true;
 			}
 			if (nonTree(modeT) && !nonTree(modeO)) {
 				if (nonTree(modeB))
-					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1);
-				add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3);
+					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
+				add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
 				unmergedPaths.add(tw.getPathString());
 				enterSubtree = false;
 				return true;
@@ -502,10 +550,10 @@ public class ResolveMerger extends ThreeWayMerger {
 			if (((modeO != 0 && !tw.idEqual(T_BASE, T_OURS)) || (modeT != 0 && !tw
 					.idEqual(T_BASE, T_THEIRS)))) {
 
-				add(tw.getRawPath(), base, DirCacheEntry.STAGE_1);
-				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2);
+				add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
+				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
 				DirCacheEntry e = add(tw.getRawPath(), theirs,
-						DirCacheEntry.STAGE_3);
+						DirCacheEntry.STAGE_3, 0, 0);
 
 				// OURS was deleted checkout THEIRS
 				if (modeO == 0) {
@@ -609,9 +657,9 @@ public class ResolveMerger extends ThreeWayMerger {
 			// a conflict occurred, the file will contain conflict markers
 			// the index will be populated with the three stages and only the
 			// workdir (if used) contains the halfways merged content
-			add(tw.getRawPath(), base, DirCacheEntry.STAGE_1);
-			add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2);
-			add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3);
+			add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
+			add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
+			add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, 0, 0);
 			mergeResults.put(tw.getPathString(), result);
 		} else {
 			// no conflict occurred, the file will contain fully merged content.