Fix getting server version and database name on failure

When the ping query fails, e.g. on credentials expired exception,
we still need to get the server version.

- Add handling of empty version string

Author: henriknyman

cypher-shell/src/main/java/org/neo4j/shell/state/BoltStateHandler.java

@@ -164,9 +164,8 @@ private void reconnect(boolean keepBookmark) {
         driver.verifyConnectivity();
 
         SessionConfig.Builder builder = SessionConfig.builder();
-        builder.withDefaultAccessMode( AccessMode.WRITE );
-        if ( !ABSENT_DB_NAME.equals( activeDatabaseNameAsSetByUser ) )
-        {
+        builder.withDefaultAccessMode(AccessMode.WRITE);
+        if (!ABSENT_DB_NAME.equals(activeDatabaseNameAsSetByUser)) {
             builder.withDatabase( activeDatabaseNameAsSetByUser );
         }
         if (session != null && keepBookmark) {
@@ -184,9 +183,17 @@ private void reconnect(boolean keepBookmark) {
 
         resetActualDbName(); // Set this to null first in case run throws an exception
         StatementResult run = session.run(query);
-        ResultSummary summary = run.consume();
-        this.version = summary.server().version();
-        updateActualDbName(summary);
+        ResultSummary summary = null;
+        try {
+            summary = run.consume();
+        } finally {
+            // Since run.consume() can throw the first time we have to go through this extra hoop to get the summary
+            if (summary == null) {
+                summary = run.consume();
+            }
+            this.version = summary.server().version();
+            updateActualDbName(summary);
+        }
     }
 
     @Nonnull

cypher-shell/src/main/java/org/neo4j/shell/util/Versions.java

@@ -26,6 +26,9 @@ public static Version version(String version) {
         if (version == null) {
             throw new AssertionError("null is not a valid version string");
         }
+        if (version.isEmpty()) {
+            return new Version(0, 0, 0);
+        }
         //remove -alpha, and -beta etc
         int offset = version.indexOf("-");
         if (offset > 0) {

cypher-shell/src/test/java/org/neo4j/shell/util/VersionsTest.java

@@ -0,0 +1,34 @@
+package org.neo4j.shell.util;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class VersionsTest
+{
+    @Test
+    public void shouldWorkForEmptyString() throws Exception {
+        assertEquals(0, Versions.version("").compareTo(Versions.version("0.0.0")));
+        assertEquals(0, Versions.majorVersion(""));
+        assertEquals(0, Versions.minorVersion(""));
+        assertEquals(0, Versions.patch(""));
+    }
+
+    @Test
+    public void shouldWorkForReleaseVersion() throws Exception {
+        String versionString = "3.4.5";
+        assertEquals(0, Versions.version(versionString).compareTo(Versions.version("3.4.5")));
+        assertEquals(3, Versions.majorVersion(versionString));
+        assertEquals(4, Versions.minorVersion(versionString));
+        assertEquals(5, Versions.patch(versionString));
+    }
+
+    @Test
+    public void shouldWorkForPreReleaseVersion() throws Exception {
+        String versionString = "3.4.55-beta99";
+        assertEquals(0, Versions.version(versionString).compareTo(Versions.version("3.4.55")));
+        assertEquals(3, Versions.majorVersion(versionString));
+        assertEquals(4, Versions.minorVersion(versionString));
+        assertEquals(55, Versions.patch(versionString));
+    }
+}