LUCENE-7607: FieldLeafComparator.setScorer() should throw IOException

lucene/CHANGES.txt

@@ -65,6 +65,9 @@ API Changes
 * LUCENE-7533: Classic query parser no longer allows autoGeneratePhraseQueries
   to be set to true when splitOnWhitespace is false (and vice-versa).
 
+* LUCENE-7607: LeafFieldComparator.setScorer and SimpleFieldComparator.setScorer
+  are declared as throwing IOException (Alan Woodward)
+
 New features
 
 * LUCENE-5867: Added BooleanSimilarity. (Robert Muir, Adrien Grand)

lucene/core/src/java/org/apache/lucene/search/LeafFieldComparator.java

@@ -114,6 +114,6 @@ public interface LeafFieldComparator {
    * 
    * @param scorer Scorer instance that you should use to
    * obtain the current hit's score, if necessary. */
-  void setScorer(Scorer scorer);
+  void setScorer(Scorer scorer) throws IOException;
 
 }

lucene/core/src/java/org/apache/lucene/search/SimpleFieldComparator.java

@@ -38,5 +38,5 @@ public abstract class SimpleFieldComparator<T> extends FieldComparator<T> implem
   }
 
   @Override
-  public void setScorer(Scorer scorer) {}
+  public void setScorer(Scorer scorer) throws IOException {}
 }

solr/core/src/java/org/apache/solr/search/CollapsingQParserPlugin.java

@@ -965,7 +965,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
 
     @Override public boolean needsScores() { return needsScores || super.needsScores(); }
 
-    public void setScorer(Scorer scorer) {
+    public void setScorer(Scorer scorer) throws IOException {
       this.collapseStrategy.setScorer(scorer);
     }
 
@@ -1147,7 +1147,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
 
     @Override public boolean needsScores() { return needsScores || super.needsScores(); }
 
-    public void setScorer(Scorer scorer) {
+    public void setScorer(Scorer scorer) throws IOException {
       this.collapseStrategy.setScorer(scorer);
     }
 
@@ -1523,7 +1523,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
       return collapsedSet;
     }
 
-    public void setScorer(Scorer scorer) {
+    public void setScorer(Scorer scorer) throws IOException {
       this.scorer = scorer;
     }
 
@@ -1952,7 +1952,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
     }
 
     @Override
-    public void setScorer(Scorer s) {
+    public void setScorer(Scorer s) throws IOException {
       super.setScorer(s);
       this.compareState.setScorer(s);
     }
@@ -2100,7 +2100,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
       return collapsedSet;
     }
 
-    public void setScorer(Scorer scorer) {
+    public void setScorer(Scorer scorer) throws IOException {
       this.scorer = scorer;
     }
 
@@ -2522,7 +2522,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
     }
 
     @Override
-    public void setScorer(Scorer s) {
+    public void setScorer(Scorer s) throws IOException {
       super.setScorer(s);
       this.compareState.setScorer(s);
     }
@@ -2673,7 +2673,7 @@ public class CollapsingQParserPlugin extends QParserPlugin {
         leafFieldComparators[clause] = fieldComparators[clause].getLeafComparator(context);
       }
     }
-    public void setScorer(Scorer s) {
+    public void setScorer(Scorer s) throws IOException {
       for (int clause = 0; clause < numClauses; clause++) {
         leafFieldComparators[clause].setScorer(s);
       }