BWC

Author: Andrey Ershov

server/src/main/java/org/elasticsearch/action/admin/cluster/snapshots/get/GetSnapshotsRequest.java

@@ -89,6 +89,10 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(MULTIPLE_REPOSITORIES_SUPPORT_ADDED)) {
             out.writeStringArray(repositories);
         } else {
+            if (repositories.length != 1) {
+                throw new IllegalArgumentException("Requesting snapshots from multiple repositories is not supported in versions prior " +
+                        "to " + MULTIPLE_REPOSITORIES_SUPPORT_ADDED.toString());
+            }
             out.writeString(repositories[0]);
         }
         out.writeStringArray(snapshots);

server/src/main/java/org/elasticsearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java

@@ -208,7 +208,8 @@ public void writeTo(StreamOutput out) throws IOException {
             }
         } else {
             if (successfulResponses.size() + failedResponses.size() != 1) {
-                throw new IllegalArgumentException("snapshots from more than one repository are requested");
+                throw new IllegalArgumentException("Requesting snapshots from multiple repositories is not supported in versions prior " +
+                        "to " + GetSnapshotsRequest.MULTIPLE_REPOSITORIES_SUPPORT_ADDED.toString());
             }
 
             if (successfulResponses.size() == 1) {