fix #2762 (#2767)

tree.go

@@ -118,11 +118,6 @@ type node struct {
 	fullPath  string
 }
 
-type skip struct {
-	path      string
-	paramNode *node
-}
-
 // Increments priority of the given child and reorders if necessary
 func (n *node) incrementChildPrio(pos int) int {
 	cs := n.children
@@ -405,7 +400,23 @@ type nodeValue struct {
 // made if a handle exists with an extra (without the) trailing slash for the
 // given path.
 func (n *node) getValue(path string, params *Params, unescape bool) (value nodeValue) {
-	var skipped *skip
+	// path: /abc/123/def
+	// level 1 router:abc
+	// level 2 router:123
+	// level 3 router:def
+	var (
+		skippedPath string
+		latestNode  = n // not found `level 2 router` use latestNode
+
+		// match '/' count
+		// matchNum < 1: `level 2 router` not found,the current node needs to be equal to latestNode
+		// matchNum >= 1: `level (2 or 3 or 4 or ...) router`: Normal handling
+		matchNum int // each match will accumulate
+	)
+	//if path == "/", no need to look for tree node
+	if len(path) == 1 {
+		matchNum = 1
+	}
 
 walk: // Outer loop for walking the tree
 	for {
@@ -418,32 +429,41 @@ walk: // Outer loop for walking the tree
 				idxc := path[0]
 				for i, c := range []byte(n.indices) {
 					if c == idxc {
-						if strings.HasPrefix(n.children[len(n.children)-1].path, ":") {
-							skipped = &skip{
-								path: prefix + path,
-								paramNode: &node{
-									path:      n.path,
-									wildChild: n.wildChild,
-									nType:     n.nType,
-									priority:  n.priority,
-									children:  n.children,
-									handlers:  n.handlers,
-									fullPath:  n.fullPath,
-								},
+						//  strings.HasPrefix(n.children[len(n.children)-1].path, ":") == n.wildChild
+						if n.wildChild {
+							skippedPath = prefix + path
+							latestNode = &node{
+								path:      n.path,
+								wildChild: n.wildChild,
+								nType:     n.nType,
+								priority:  n.priority,
+								children:  n.children,
+								handlers:  n.handlers,
+								fullPath:  n.fullPath,
 							}
 						}
 
 						n = n.children[i]
+
+						// match '/', If this condition is matched, the next route is found
+						if (len(n.fullPath) != 0 && n.wildChild) || path[len(path)-1] == '/' {
+							matchNum++
+						}
 						continue walk
 					}
 				}
 
+				// level 2 router not found,the current node needs to be equal to latestNode
+				if matchNum < 1 {
+					n = latestNode
+				}
+
 				// If there is no wildcard pattern, recommend a redirection
 				if !n.wildChild {
 					// Nothing found.
 					// We can recommend to redirect to the same URL without a
 					// trailing slash if a leaf exists for that path.
-					value.tsr = (path == "/" && n.handlers != nil)
+					value.tsr = path == "/" && n.handlers != nil
 					return
 				}
 
@@ -483,6 +503,18 @@ walk: // Outer loop for walking the tree
 						if len(n.children) > 0 {
 							path = path[end:]
 							n = n.children[0]
+							// next node,the latestNode needs to be equal to currentNode and handle next router
+							latestNode = n
+							// not found router in (level 1 router and handle next node),skippedPath cannot execute
+							// example:
+							// * /:cc/cc
+							// call /a/cc 	     expectations:match/200      Actual:match/200
+							// call /a/dd 	     expectations:unmatch/404    Actual: panic
+							// call /addr/dd/aa  expectations:unmatch/404    Actual: panic
+							// skippedPath: It can only be executed if the secondary route is not found
+							// matchNum: Go to the next level of routing tree node search,need add matchNum
+							skippedPath = ""
+							matchNum++
 							continue walk
 						}
 
@@ -535,6 +567,10 @@ walk: // Outer loop for walking the tree
 		}
 
 		if path == prefix {
+			// level 2 router not found and latestNode.wildChild is true
+			if matchNum < 1 && latestNode.wildChild {
+				n = latestNode.children[len(latestNode.children)-1]
+			}
 			// We should have reached the node containing the handle.
 			// Check if this node has a handle registered.
 			if value.handlers = n.handlers; value.handlers != nil {
@@ -564,18 +600,18 @@ walk: // Outer loop for walking the tree
 			return
 		}
 
-		if path != "/" && skipped != nil && strings.HasSuffix(skipped.path, path) {
-			path = skipped.path
-			n = skipped.paramNode
-			skipped = nil
+		// path != "/" && skippedPath != ""
+		if len(path) != 1 && len(skippedPath) > 0 && strings.HasSuffix(skippedPath, path) {
+			path = skippedPath
+			n = latestNode
+			skippedPath = ""
 			continue walk
 		}
 
 		// Nothing found. We can recommend to redirect to the same URL with an
 		// extra trailing slash if a leaf exists for that path
-		value.tsr = (path == "/") ||
-			(len(prefix) == len(path)+1 && prefix[len(path)] == '/' &&
-				path == prefix[:len(prefix)-1] && n.handlers != nil)
+		value.tsr = path == "/" ||
+			(len(prefix) == len(path)+1 && n.handlers != nil)
 		return
 	}
 }