From ed6c90f03ffe71a34ea2c27ba2d760f328842145 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Thu, 24 Jun 2021 19:16:59 +0200
Subject: [PATCH] chore: add logging for print_backend failures

---
 shell/browser/api/electron_api_printing.cc    |  5 +++-
 .../browser/api/electron_api_web_contents.cc  | 26 ++++++++++++++-----
 shell/browser/api/electron_api_web_contents.h |  3 ++-
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/shell/browser/api/electron_api_printing.cc b/shell/browser/api/electron_api_printing.cc
index a73005f735793..6841aec62b3a6 100644
--- a/shell/browser/api/electron_api_printing.cc
+++ b/shell/browser/api/electron_api_printing.cc
@@ -47,7 +47,10 @@ printing::PrinterList GetPrinterList() {
     // TODO(deepak1556): Deprecate this api in favor of an
     // async version and post a non blocing task call.
     base::ThreadRestrictions::ScopedAllowIO allow_io;
-    print_backend->EnumeratePrinters(&printers);
+    printing::mojom::ResultCode code =
+        print_backend->EnumeratePrinters(&printers);
+    if (code != printing::mojom::ResultCode::kSuccess)
+      LOG(INFO) << "Failed to enumerate printers";
   }
   return printers;
 }
diff --git a/shell/browser/api/electron_api_web_contents.cc b/shell/browser/api/electron_api_web_contents.cc
index 2bfa4fff2a591..26fba2d2aec2e 100644
--- a/shell/browser/api/electron_api_web_contents.cc
+++ b/shell/browser/api/electron_api_web_contents.cc
@@ -424,7 +424,7 @@ bool IsDeviceNameValid(const std::u16string& device_name) {
 #endif
 }
 
-std::u16string GetDefaultPrinterAsync() {
+std::pair<std::string, std::u16string> GetDefaultPrinterAsync() {
 #if defined(OS_WIN)
   // Blocking is needed here because Windows printer drivers are oftentimes
   // not thread-safe and have to be accessed on the UI thread.
@@ -435,18 +435,26 @@ std::u16string GetDefaultPrinterAsync() {
       printing::PrintBackend::CreateInstance(
           g_browser_process->GetApplicationLocale());
   std::string printer_name;
-  print_backend->GetDefaultPrinterName(printer_name);
+  printing::mojom::ResultCode code =
+      print_backend->GetDefaultPrinterName(printer_name);
+  if (code != printing::mojom::ResultCode::kSuccess)
+    return std::make_pair("Failed to get default printer name",
+                          std::u16string());
 
   // Some devices won't have a default printer, so we should
   // also check for existing printers and pick the first
   // one should it exist.
   if (printer_name.empty()) {
     printing::PrinterList printers;
-    print_backend->EnumeratePrinters(&printers);
+    printing::mojom::ResultCode code =
+        print_backend->EnumeratePrinters(&printers);
+    if (code != printing::mojom::ResultCode::kSuccess)
+      return std::make_pair("Failed to enumerate printers", std::u16string());
     if (!printers.empty())
       printer_name = printers.front().printer_name;
   }
-  return base::UTF8ToUTF16(printer_name);
+
+  return std::make_pair(std::string(), base::UTF8ToUTF16(printer_name));
 }
 
 // Copied from
@@ -2409,7 +2417,7 @@ void WebContents::OnGetDefaultPrinter(
     printing::CompletionCallback print_callback,
     std::u16string device_name,
     bool silent,
-    std::u16string default_printer) {
+    std::pair<std::string, std::u16string> info) {
   // The content::WebContents might be already deleted at this point, and the
   // PrintViewManagerElectron class does not do null check.
   if (!web_contents()) {
@@ -2418,8 +2426,12 @@ void WebContents::OnGetDefaultPrinter(
     return;
   }
 
-  std::u16string printer_name =
-      device_name.empty() ? default_printer : device_name;
+  if (!info.first.empty()) {
+    std::move(print_callback).Run(false, info.first);
+    return;
+  }
+
+  std::u16string printer_name = info.second.empty() ? info.second : device_name;
 
   // If there are no valid printers available on the network, we bail.
   if (printer_name.empty() || !IsDeviceNameValid(printer_name)) {
diff --git a/shell/browser/api/electron_api_web_contents.h b/shell/browser/api/electron_api_web_contents.h
index dcfe9fcc40bbc..a8bb558174cf9 100644
--- a/shell/browser/api/electron_api_web_contents.h
+++ b/shell/browser/api/electron_api_web_contents.h
@@ -215,7 +215,8 @@ class WebContents : public gin::Wrappable<WebContents>,
                            printing::CompletionCallback print_callback,
                            std::u16string device_name,
                            bool silent,
-                           std::u16string default_printer);
+                           // <error, default_printer_name>
+                           std::pair<std::string, std::u16string> info);
   void Print(gin::Arguments* args);
   // Print current page as PDF.
   v8::Local<v8::Promise> PrintToPDF(base::DictionaryValue settings);