Fix path matching logic for ErrorHandler assignment

Author: duhnnie

app.go

@@ -1041,9 +1041,13 @@ func (app *App) ErrorHandler(ctx *Ctx, err error) error {
 		mountedPrefixParts int
 	)
 
+	normalizedPath := utils.AddTrailingSlash(ctx.Path())
+
 	for _, prefix := range app.mountFields.appListKeys {
 		subApp := app.mountFields.appList[prefix]
-		if prefix != "" && strings.HasPrefix(ctx.Path(), prefix) {
+		normalizedPrefix := utils.AddTrailingSlash(prefix)
+
+		if prefix != "" && strings.HasPrefix(normalizedPath, normalizedPrefix) {
 			parts := len(strings.Split(prefix, "/"))
 			if mountedPrefixParts <= parts {
 				if subApp.configured.ErrorHandler != nil {

utils/strings.go

@@ -4,6 +4,8 @@
 
 package utils
 
+import "strings"
+
 // ToLower converts ascii string to lower-case
 func ToLower(b string) string {
 	res := make([]byte, len(b))
@@ -73,3 +75,11 @@ func EqualFold(b, s string) bool {
 	}
 	return true
 }
+
+func AddTrailingSlash(s string) string {
+	if strings.HasSuffix(s, "/") {
+		return s
+	}
+
+	return s + "/"
+}