improve robustness of LocalRepository#blameUnmergedFile #3

src/de/uni_passau/fim/seibt/gitwrapper/repo/LocalRepository.java

@@ -23,6 +23,10 @@ import java.util.stream.Collectors;
 import de.uni_passau.fim.seibt.gitwrapper.process.ProcessExecutor.ExecRes;
 import org.apache.commons.io.FileUtils;
 
+import static de.uni_passau.fim.seibt.gitwrapper.repo.LocalRepository.ConflictMarker.CONFLICT_END;
+import static de.uni_passau.fim.seibt.gitwrapper.repo.LocalRepository.ConflictMarker.CONFLICT_MIDDLE;
+import static de.uni_passau.fim.seibt.gitwrapper.repo.LocalRepository.ConflictMarker.CONFLICT_START;
+
 /**
  * A git {@link Repository}.
  */
@@ -46,9 +50,24 @@ public class LocalRepository extends Repository {
     // The type returned for commits by 'git cat-file -t".
     private static final String TYPE_COMMIT = "commit";
 
-    private static final String CONFLICT_START = "<<<<<<<";
-    private static final String CONFLICT_MIDDLE = "=======";
-    private static final String CONFLICT_END = ">>>>>>>";
+    /**
+     * An enumeration of the three possible conflict markers in an unmerged file.
+     */
+    enum ConflictMarker {
+        CONFLICT_START("<<<<<<<"),
+        CONFLICT_MIDDLE("======="),
+        CONFLICT_END(">>>>>>>");
+
+        /**
+         * The expected characters at the beginning of a line representing a
+         * conflict marker.
+         */
+        public final String prefix;
+
+        ConflictMarker(String prefix) {
+            this.prefix = prefix;
+        }
+    }
 
     // The prefixes of the full symbolic names of (remote) branches.
     private static final String FULL_SYMBOLIC_BRANCH = "refs/heads/";
@@ -472,22 +491,22 @@ public class LocalRepository extends Repository {
 
         List<BlameLine> left = null;
         List<BlameLine> right = null;
-        String lastMarker = null;
+        ConflictMarker lastMarker = null;
 
         for (BlameLine line : blame.get()) {
-            if (line.line.startsWith(CONFLICT_START)) {
+            if (line.line.startsWith(CONFLICT_START.prefix)) {
                 left = new ArrayList<>();
                 right = new ArrayList<>();
                 lastMarker = CONFLICT_START;
-            } else if (line.line.startsWith(CONFLICT_MIDDLE)) {
+            } else if (lastMarker == CONFLICT_START && line.line.startsWith(CONFLICT_MIDDLE.prefix)) {
                 lastMarker = CONFLICT_MIDDLE;
-            } else if (line.line.startsWith(CONFLICT_END)) {
+            } else if (lastMarker == CONFLICT_MIDDLE && line.line.startsWith(CONFLICT_END.prefix)) {
                 conflicts.add(new MergeConflict(left, right));
                 lastMarker = CONFLICT_END;
-            } else if (CONFLICT_START.equals(lastMarker)) {
-                assert left != null; left.add(line);
-            } else if (CONFLICT_MIDDLE.equals(lastMarker)) {
-                assert right != null; right.add(line);
+            } else if (CONFLICT_START == lastMarker) {
+                left.add(line);
+            } else if (CONFLICT_MIDDLE == lastMarker) {
+                right.add(line);
             }
         }