prevent double enconding in path parameters

.gitignore

@@ -5,3 +5,4 @@ count.out
 test
 profile.out
 tmp.out
+*.iml

gin.go

@@ -603,7 +603,7 @@ func (engine *Engine) handleHTTPRequest(c *Context) {
 		}
 		root := t[i].root
 		// Find route in tree
-		value := root.getValue(rPath, c.params, c.skippedNodes, unescape)
+		value := root.getValue(rPath, c.params, c.skippedNodes, unescape, engine.RedirectFixedPath)
 		if value.params != nil {
 			c.Params = *value.params
 		}
@@ -631,7 +631,7 @@ func (engine *Engine) handleHTTPRequest(c *Context) {
 			if tree.method == httpMethod {
 				continue
 			}
-			if value := tree.root.getValue(rPath, nil, c.skippedNodes, unescape); value.handlers != nil {
+			if value := tree.root.getValue(rPath, nil, c.skippedNodes, unescape, engine.RedirectFixedPath); value.handlers != nil {
 				c.handlers = engine.allNoMethod
 				serveError(c, http.StatusMethodNotAllowed, default405Body)
 				return

tree.go

@@ -415,7 +415,7 @@ type skippedNode struct {
 // If no handle can be found, a TSR (trailing slash redirect) recommendation is
 // made if a handle exists with an extra (without the) trailing slash for the
 // given path.
-func (n *node) getValue(path string, params *Params, skippedNodes *[]skippedNode, unescape bool) (value nodeValue) {
+func (n *node) getValue(path string, params *Params, skippedNodes *[]skippedNode, unescape, redirectFixedPath bool) (value nodeValue) {
 	var globalParamsCount int16
 
 walk: // Outer loop for walking the tree
@@ -504,8 +504,21 @@ walk: // Outer loop for walking the tree
 						*value.params = (*value.params)[:i+1]
 						val := path[:end]
 						if unescape {
-							if v, err := url.QueryUnescape(val); err == nil {
+							v := val
-								val = v
+							for {
+								beforeDecoding := v
+								if decoded, err := url.QueryUnescape(v); err == nil {
+									v = decoded
+								} else {
+									break
+								}
+								if beforeDecoding == v {
+									val = v
+									break
+								}
+							}
+							if redirectFixedPath {
+								val = cleanPath(val)
 							}
 						}
 						(*value.params)[i] = Param{
@@ -550,8 +563,21 @@ walk: // Outer loop for walking the tree
 						*value.params = (*value.params)[:i+1]
 						val := path
 						if unescape {
-							if v, err := url.QueryUnescape(path); err == nil {
+							v := val
-								val = v
+							for {
+								beforeDecoding := v
+								if decoded, err := url.QueryUnescape(v); err == nil {
+									v = decoded
+								} else {
+									break
+								}
+								if beforeDecoding == v {
+									val = v
+									break
+								}
+							}
+							if redirectFixedPath {
+								val = cleanPath(val)
 							}
 						}
 						(*value.params)[i] = Param{

tree_test.go

@@ -38,14 +38,15 @@ func getSkippedNodes() *[]skippedNode {
 	return &ps
 }
 
-func checkRequests(t *testing.T, tree *node, requests testRequests, unescapes ...bool) {
+func checkRequests(t *testing.T, tree *node, requests testRequests, redirectFixedPath bool, unescapes ...bool) {
 	unescape := false
+
 	if len(unescapes) >= 1 {
 		unescape = unescapes[0]
 	}
 
 	for _, request := range requests {
-		value := tree.getValue(request.path, getParams(), getSkippedNodes(), unescape)
+		value := tree.getValue(request.path, getParams(), getSkippedNodes(), unescape, redirectFixedPath)
 
 		if value.handlers == nil {
 			if !request.nilHandler {
@@ -130,7 +131,7 @@ func TestTreeAddAndGet(t *testing.T) {
 		{"/ab", false, "/ab", nil},
 		{"/α", false, "/α", nil},
 		{"/β", false, "/β", nil},
-	})
+	}, false)
 
 	checkPriorities(t, tree)
 }
@@ -315,7 +316,7 @@ func TestTreeWildcard(t *testing.T) {
 		{"/get/abc/123abg/test", false, "/get/abc/123abg/:param", Params{Param{Key: "param", Value: "test"}}},
 		{"/get/abc/123abf/testss", false, "/get/abc/123abf/:param", Params{Param{Key: "param", Value: "testss"}}},
 		{"/get/abc/123abfff/te", false, "/get/abc/123abfff/:param", Params{Param{Key: "param", Value: "te"}}},
-	})
+	}, false)
 
 	checkPriorities(t, tree)
 }
@@ -352,7 +353,7 @@ func TestUnescapeParameters(t *testing.T) {
 		{"/info/slash%2Fgordon/project/Project%20%231", false, "/info/:user/project/:project", Params{Param{Key: "user", Value: "slash/gordon"}, Param{Key: "project", Value: "Project #1"}}},
 		{"/info/slash%%%%", false, "/info/:user", Params{Param{Key: "user", Value: "slash%%%%"}}},
 		{"/info/slash%%%%2Fgordon/project/Project%%%%20%231", false, "/info/:user/project/:project", Params{Param{Key: "user", Value: "slash%%%%2Fgordon"}, Param{Key: "project", Value: "Project%%%%20%231"}}},
-	}, unescape)
+	}, false, unescape)
 
 	checkPriorities(t, tree)
 }
@@ -482,7 +483,7 @@ func TestTreeDuplicatePath(t *testing.T) {
 		{"/src/some/file.png", false, "/src/*filepath", Params{Param{"filepath", "/some/file.png"}}},
 		{"/search/someth!ng+in+ünìcodé", false, "/search/:query", Params{Param{"query", "someth!ng+in+ünìcodé"}}},
 		{"/user_gopher", false, "/user_:name", Params{Param{"name", "gopher"}}},
-	})
+	}, false)
 }
 
 func TestEmptyWildcardName(t *testing.T) {
@@ -636,7 +637,7 @@ func TestTreeTrailingSlashRedirect(t *testing.T) {
 	}
 
 	for _, route := range tsrRoutes {
-		value := tree.getValue(route, nil, getSkippedNodes(), false)
+		value := tree.getValue(route, nil, getSkippedNodes(), false, false)
 		if value.handlers != nil {
 			t.Fatalf("non-nil handler for TSR route '%s", route)
 		} else if !value.tsr {
@@ -657,7 +658,7 @@ func TestTreeTrailingSlashRedirect(t *testing.T) {
 		"/foo/p/p",
 	}
 	for _, route := range noTsrRoutes {
-		value := tree.getValue(route, nil, getSkippedNodes(), false)
+		value := tree.getValue(route, nil, getSkippedNodes(), false, false)
 		if value.handlers != nil {
 			t.Fatalf("non-nil handler for No-TSR route '%s", route)
 		} else if value.tsr {
@@ -676,7 +677,7 @@ func TestTreeRootTrailingSlashRedirect(t *testing.T) {
 		t.Fatalf("panic inserting test route: %v", recv)
 	}
 
-	value := tree.getValue("/", nil, getSkippedNodes(), false)
+	value := tree.getValue("/", nil, getSkippedNodes(), false, false)
 	if value.handlers != nil {
 		t.Fatalf("non-nil handler")
 	} else if value.tsr {
@@ -856,7 +857,7 @@ func TestTreeInvalidNodeType(t *testing.T) {
 
 	// normal lookup
 	recv := catchPanic(func() {
-		tree.getValue("/test", nil, getSkippedNodes(), false)
+		tree.getValue("/test", nil, getSkippedNodes(), false, false)
 	})
 	if rs, ok := recv.(string); !ok || rs != panicMsg {
 		t.Fatalf("Expected panic '"+panicMsg+"', got '%v'", recv)
@@ -881,7 +882,7 @@ func TestTreeInvalidParamsType(t *testing.T) {
 	params := make(Params, 0)
 
 	// try to trigger slice bounds out of range with capacity 0
-	tree.getValue("/test", &params, getSkippedNodes(), false)
+	tree.getValue("/test", &params, getSkippedNodes(), false, false)
 }
 
 func TestTreeWildcardConflictEx(t *testing.T) {