Issue swagger-api#1035

buildUrl:
1. Trim ".." from root as well
2. If rel starts with "/", trim root to domain

Author: jweisman

modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/util/RefUtils.java

@@ -114,6 +114,9 @@ public static String buildUrl(String rootPath, String relativePath) {
         if(!"".equals(rootPathParts[rootPathParts.length - 1])) {
             trimRoot = 1;
         }
+        if("".equals(relPathParts[0])) {
+            trimRel = 1; trimRoot = rootPathParts.length-3;
+        }        
         for(int i = 0; i < rootPathParts.length; i++) {
             if("".equals(rootPathParts[i])) {
                 trimRel += 1;
@@ -127,7 +130,7 @@ public static String buildUrl(String rootPath, String relativePath) {
                 trimRel += 1;
             }
             else if ("..".equals(relPathParts[i])) {
-                trimRel += 1;
+                trimRel += 1; trimRoot += 1;
             }
         }
 
@@ -136,7 +139,7 @@ else if ("..".equals(relPathParts[i])) {
         System.arraycopy(relPathParts,
                 trimRel,
                 outputParts,
-                rootPathParts.length - trimRoot + trimRel - 1,
+                rootPathParts.length - trimRoot,
                 relPathParts.length - trimRel);
 
         return StringUtils.join(outputParts, "/");

modules/swagger-parser-v3/src/test/java/io/swagger/v3/parser/util/RefUtilsTest.java

@@ -293,4 +293,12 @@ public void testPathJoin1() {
         // relative locations
         assertEquals(ExternalRefProcessor.join("./foo#/definitions/Foo", "./bar#/definitions/Bar"), "./bar#/definitions/Bar");
     }
+    
+    @Test 
+    public void testPathJoin2() {
+        assertEquals(RefUtils.buildUrl("http://foo.bar.com/my/dir/file.yaml", "../newFile.yaml"), "http://foo.bar.com/my/newFile.yaml");
+        assertEquals(RefUtils.buildUrl("http://foo.bar.com/my/dir/file.yaml", "../../newFile.yaml"), "http://foo.bar.com/newFile.yaml");
+        assertEquals(RefUtils.buildUrl("http://foo.bar.com/my/dir/file.yaml", "/newFile.yaml"), "http://foo.bar.com/newFile.yaml");
+        assertEquals(RefUtils.buildUrl("http://foo.bar.com/my/dir/file.yaml", "/my/newFile.yaml"), "http://foo.bar.com/my/newFile.yaml");
+    }
 }