[patch] fix infinite recursion on structured response failure

responses.go

@@ -7,6 +7,10 @@ import (
 	"net/http"
 )
 
+var (
+	jsonErrPayload = []byte{}
+)
+
 // ErrorData used to render the error page
 type ErrorData struct {
 	ErrCode        int
@@ -69,29 +73,31 @@ func SendResponse(w http.ResponseWriter, data interface{}, rCode int) {
 	w = crwAsserter(w, rCode)
 	w.Header().Add(HeaderContentType, JSONContentType)
 	err := json.NewEncoder(w).Encode(dOutput{Data: data, Status: rCode})
-	if err != nil {
-		/*
-			In case of encoding error, send "internal server error" and
-			log the actual error.
-		*/
-		R500(w, ErrInternalServer)
-		LOGHANDLER.Error(err)
+	if err == nil {
+		return
 	}
+
+	// assuming the error was related to JSON encoding, so reattempting to respond
+	// with a static payload. This could still fail in case of network write or other error(s)
+	w = crwAsserter(w, http.StatusInternalServerError)
+	_, _ = w.Write(jsonErrPayload)
+	LOGHANDLER.Error(err)
 }
 
 // SendError is used to respond to any request with an error
 func SendError(w http.ResponseWriter, data interface{}, rCode int) {
 	w = crwAsserter(w, rCode)
 	w.Header().Add(HeaderContentType, JSONContentType)
 	err := json.NewEncoder(w).Encode(errOutput{data, rCode})
-	if err != nil {
-		/*
-			In case of encoding error, send "internal server error" and
-			log the actual error.
-		*/
-		R500(w, ErrInternalServer)
-		LOGHANDLER.Error(err)
+	if err == nil {
+		return
 	}
+
+	// assuming the error was related to JSON encoding, so reattempting to respond
+	// with a static payload. This could still fail in case of network write or other error(s)
+	w = crwAsserter(w, http.StatusInternalServerError)
+	_, _ = w.Write(jsonErrPayload)
+	LOGHANDLER.Error(err)
 }
 
 // Render is used for rendering templates (HTML)

router.go

@@ -3,6 +3,7 @@ package webgo
 import (
 	"bufio"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"net"
@@ -21,6 +22,15 @@ type httpResponseWriter interface {
 }
 
 func init() {
+	var err error
+	jsonErrPayload, err = json.Marshal(errOutput{
+		Errors: ErrInternalServer,
+		Status: http.StatusInternalServerError,
+	})
+	if err != nil {
+		panic(err)
+	}
+
 	// ensure the custom response writer implements all the required functions
 	crw := &customResponseWriter{}
 	_ = httpResponseWriter(crw)