preserve query string from the request when building reivision redirect (#2494)

fixes #2492

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/web/PageConfig.java

@@ -1288,6 +1288,11 @@ public String getRevisionLocation(String revStr) {
         sb.append("?r=");
         sb.append(Util.URIEncode(revStr));
 
+        if (req.getQueryString() != null) {
+            sb.append("&");
+            sb.append(req.getQueryString());
+        }
+
         return sb.toString();
     }
 

opengrok-indexer/src/test/java/org/opengrok/indexer/web/PageConfigTest.java

@@ -246,8 +246,8 @@ public String getParameter(String name) {
     public void testGetLatestRevisionValid() {
         DummyHttpServletRequest req1 = new DummyHttpServletRequest() {
             @Override
-                public String getPathInfo() {
-                    return "/git/main.c";
+            public String getPathInfo() {
+                return "/git/main.c";
             }
         };
 
@@ -257,6 +257,58 @@ public String getPathInfo() {
         assertEquals("aa35c258", rev);
     }
 
+    @Test
+    public void testGetRevisionLocation() {
+        DummyHttpServletRequest req1 = new DummyHttpServletRequest() {
+            @Override
+            public String getPathInfo() {
+                return "/git/main.c";
+            }
+
+            @Override
+            public String getContextPath() {
+                return "source";
+            }
+
+            @Override
+            public String getQueryString() {
+                return "a=true";
+            }
+        };
+
+        PageConfig cfg = PageConfig.get(req1);
+
+        String location = cfg.getRevisionLocation(cfg.getLatestRevision());
+        assertNotNull(location);
+        assertEquals("source/xref/git/main.c?r=aa35c258&a=true", location);
+    }
+
+    @Test
+    public void testGetRevisionLocationNullQuery() {
+        DummyHttpServletRequest req1 = new DummyHttpServletRequest() {
+            @Override
+            public String getPathInfo() {
+                return "/git/main.c";
+            }
+
+            @Override
+            public String getContextPath() {
+                return "source";
+            }
+
+            @Override
+            public String getQueryString() {
+                return null;
+            }
+        };
+
+        PageConfig cfg = PageConfig.get(req1);
+
+        String location = cfg.getRevisionLocation(cfg.getLatestRevision());
+        assertNotNull(location);
+        assertEquals("source/xref/git/main.c?r=aa35c258", location);
+    }
+
     @Test
     public void testGetLatestRevisionNotValid() {
         DummyHttpServletRequest req2 = new DummyHttpServletRequest() {