Merge pull request #238 from setlog/fix/server_error_messages

More precise error messages in gui

Author: MMulthaupt

CHANGES.md

@@ -14,6 +14,7 @@
 * `hasher` will no longer create a directory if a non-existing one is passed as an argument.
 * trivrost will no longer attempt to repeat range requests to a host after it has failed to conformly respond while displaying the confusing message `Taking longer than usual: HTTP Status 200` and will now fail immediately in such cases instead.
 * trivrost will no longer fail to comply with HTTP 2 strictly using lower-case HTTP Header names. This had been caused by methods of `http.Header` still being oriented around HTTP 1 canonical header names due to Go's backwards compatibility promise.
+* Instead of always showing 'Cannot reach server' to the user, show more precise/useful messages on connection issues.
 
 ## 1.4.6 (2021-01-25)
 ### Fixes

cmd/launcher/gui/gui_progress_handler.go

@@ -2,6 +2,7 @@ package gui
 
 import (
 	"fmt"
+	"strings"
 	"sync"
 
 	"net/http"
@@ -72,7 +73,14 @@ func (handler *GuiDownloadProgressHandler) HandleHttpGetError(fromURL string, er
 	handler.progressMutex.Lock()
 	defer handler.progressMutex.Unlock()
 	handler.problemUrl = fromURL
-	NotifyProblem("Cannot reach server", false)
+
+	if strings.Contains(err.Error(), "x509: ") {
+		NotifyProblem("Certificate (X.509) problem", false)
+	} else if strings.Contains(err.Error(), "dial tcp: lookup") && strings.Contains(err.Error(), "no such host") {
+		NotifyProblem("Unable to resolve hostname", false)
+	} else {
+		NotifyProblem("Connection problem", false)
+	}
 }
 
 func (handler *GuiDownloadProgressHandler) HandleBadHttpResponse(fromURL string, code int) {