Print Preview: Fix failure to save with long page title

ui/shell_dialogs/select_file_dialog.cc

Index: ui/shell_dialogs/select_file_dialog.cc
diff --git a/ui/shell_dialogs/select_file_dialog.cc b/ui/shell_dialogs/select_file_dialog.cc
index 1aa7a0e26164079e0563943180353d03cdb6c861..f58a9adc5d462e10da467effd287d35da1cc3633 100644
--- a/ui/shell_dialogs/select_file_dialog.cc
+++ b/ui/shell_dialogs/select_file_dialog.cc
@@ -5,6 +5,7 @@
 #include "ui/shell_dialogs/select_file_dialog.h"
 
 #include <stddef.h>
+#include <algorithm>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ -21,6 +22,34 @@ namespace {
 // Optional dialog factory. Leaked.
 ui::SelectFileDialogFactory* dialog_factory_ = NULL;
 
+// Returns a file path with a base name at most 255 characters long. This
+// is the limit on Windows and Linux, and on Windows the system file
+// selection dialog will fail to open if the file name exceeds 255 characters.
+base::FilePath GetShortenedFilePath(const base::FilePath& path) {
+  base::FilePath filename = path.BaseName();
+  base::FilePath short_path = path;
+  const size_t kMaxNameLength = 255;
+  if (filename.value().length() <= kMaxNameLength)
+    return short_path;
+  base::FilePath::StringType extension = filename.FinalExtension();
+  filename = filename.RemoveFinalExtension();
+  // 1 for . plus 12 for longest known extension.
+  size_t max_extension_length = 13;
+  if (filename.value().length() < kMaxNameLength) {
+    max_extension_length = std::max(max_extension_length,
+                                    kMaxNameLength - filename.value().length());
+  }
+  if (extension.length() >= max_extension_length) {

[Lei Zhang, 2017/04/13 21:53:09]

Just > now?

[rbpotter, 2017/04/13 23:02:11]

Done.

+    // Take the first max_extension_length characters (this will be the
+    // leading '.' plus the next max_extension_length - 1).
+    extension = extension.substr(0, max_extension_length);

[Lei Zhang, 2017/04/13 21:53:09]

Can we trim by using resize()? Ditto on line 48.

[rbpotter, 2017/04/13 23:02:10]

Done.

+  }
+  short_path = path.DirName().Append(
+      filename.value().substr(0, kMaxNameLength - extension.length()));
+  short_path = short_path.AddExtension(extension);
+  return short_path;
+}
+
 }  // namespace
 
 namespace ui {
@@ -98,8 +127,10 @@ void SelectFileDialog::SelectFile(
     return;
   }
 
+  base::FilePath path = GetShortenedFilePath(default_path);
+
   // Call the platform specific implementation of the file selection dialog.
-  SelectFileImpl(type, title, default_path, file_types, file_type_index,
+  SelectFileImpl(type, title, path, file_types, file_type_index,
                  default_extension, owning_window, params);
 }