[vte] widget: Use safe getter

[Christian Persch <chpe src gnome org>]

commit a1fbb9df57492c4d3c298099f0a242261be7ccc3
Author: Christian Persch <chpe src gnome org>
Date:   Thu Oct 22 20:34:52 2020 +0200

    widget: Use safe getter

 src/glib-glue.hh |  2 ++
 src/widget.cc    | 16 +++++++---------
 2 files changed, 9 insertions(+), 9 deletions(-)
---
diff --git a/src/glib-glue.hh b/src/glib-glue.hh
index d075817d..ab620338 100644
--- a/src/glib-glue.hh
+++ b/src/glib-glue.hh
@@ -40,6 +40,7 @@ take_free_ptr(T* ptr)
 }
 
 using StringPtr = FreePtr<char>;
+using StringGetter = vte::ValueGetter<StringPtr, char*, nullptr>;
 
 inline StringPtr
 take_string(char* str)
@@ -54,6 +55,7 @@ dup_string(char const* str)
 }
 
 using StrvPtr = vte::FreeablePtr<char*, decltype(&g_strfreev), &g_strfreev>;
+using StrvGetter = vte::ValueGetter<StrvPtr, char**, nullptr>;
 
 inline StrvPtr
 take_strv(char** strv)
diff --git a/src/widget.cc b/src/widget.cc
index 31061413..c774ec29 100644
--- a/src/widget.cc
+++ b/src/widget.cc
@@ -348,20 +348,18 @@ Widget::im_focus_out() noexcept
 void
 Widget::im_preedit_changed() noexcept
 {
-        char* str = nullptr;
-       int cursorpos = 0;
-
+        auto str = vte::glib::StringPtr{};
         auto attrs = vte::Freeable<PangoAttrList>{};
-        gtk_im_context_get_preedit_string(m_im_context.get(), &str,
+        auto cursorpos = 0;
+        gtk_im_context_get_preedit_string(m_im_context.get(),
+                                          vte::glib::StringGetter{str},
                                           vte::get_freeable(attrs),
                                           &cursorpos);
         _vte_debug_print(VTE_DEBUG_EVENTS, "Input method pre-edit changed (%s,%d).\n",
-                         str, cursorpos);
-
-        if (str != nullptr)
-                m_terminal->im_preedit_changed(str, cursorpos, std::move(attrs));
+                         str.get(), cursorpos);
 
-        g_free(str);
+        if (str)
+                m_terminal->im_preedit_changed(str.get(), cursorpos, std::move(attrs));
 }
 
 void