diff --git a/src/dialog.cc b/src/dialog.cc
index 109f142..4f4faf1 100644
--- a/src/dialog.cc
+++ b/src/dialog.cc
@@ -275,13 +275,15 @@ const char *a_Dialog_select_file(const char *title,
  *
  * @return pointer to chosen filename, or NULL on Cancel.
  */
-char *a_Dialog_open_file(const char *title,
-                         const char *pattern, const char *fname)
+std::optional< std::string >
+a_Dialog_open_file(const std::string &title,
+		const std::optional< std::string > &pattern, const std::string &fname)
 {
    const char *fc_name;
-
-   fc_name = fl_file_chooser(title, pattern, fname);
-   return (fc_name) ? a_Misc_escape_chars(fc_name, "% #") : NULL;
+   const char *const pat= pattern.has_value() ? pattern.value().c_str() : nullptr;
+   fc_name = fl_file_chooser(title.c_str(), pat, fname.c_str());
+   if( not fc_name ) return std::nullopt;
+   return  a_Misc_escape_chars(fc_name, "% #");
 }
 
 /**
diff --git a/src/dialog.hh b/src/dialog.hh
index b5cb89d..15d7e18 100644
--- a/src/dialog.hh
+++ b/src/dialog.hh
@@ -18,8 +18,14 @@ const char *a_Dialog_save_file(const char *title,
                                const char *pattern, const char *fname);
 const char *a_Dialog_select_file(const char *title,
                                  const char *pattern, const char *fname);
-char *a_Dialog_open_file(const char *title,
-                         const char *pattern, const char *fname);
+#ifdef __cplusplus
+extern "C++" {
+#include <optional>
+#include <string>
+std::optional< std::string > a_Dialog_open_file(const std::string &title,
+                         const std::optional< std::string > &pattern, const std::string &fname);
+}
+#endif
 void a_Dialog_text_window(const char *title, const char *txt);
 
 #ifdef __cplusplus
diff --git a/src/dillo.cc b/src/dillo.cc
index 33f9839..afa94d5 100644
--- a/src/dillo.cc
+++ b/src/dillo.cc
@@ -370,7 +370,8 @@ static void setColors()
  */
 static DilloUrl *makeStartUrl(char *str, bool local)
 {
-   char *url_str, *p;
+   std::string url_str;
+   char *p;
    DilloUrl *start_url;
 
    /* Relative path to a local file? */
@@ -380,14 +381,15 @@ static DilloUrl *makeStartUrl(char *str, bool local)
    if (access(p, F_OK) == 0) {
       /* absolute path may have non-URL characters */
       url_str = a_Misc_escape_chars(p, "% #");
-      start_url = a_Url_new(url_str + 1, "file:/");
+      start_url = a_Url_new(url_str.c_str() + 1, "file:/");
    } else {
       /* Not a file, filter URL string */
-      url_str = a_Url_string_strip_delimiters(str);
-      start_url = a_Url_new(url_str, NULL);
+      char *const tmp= a_Url_string_strip_delimiters(str);
+      url_str = tmp;
+	  dFree( tmp );
+      start_url = a_Url_new(url_str.c_str(), NULL);
    }
    dFree(p);
-   dFree(url_str);
 
    if (local)
       a_Url_set_flags(start_url, URL_FLAGS(start_url) | URL_SpamSafe);
diff --git a/src/misc.cc b/src/misc.cc
index 3dc1806..386c6d4 100644
--- a/src/misc.cc
+++ b/src/misc.cc
@@ -23,27 +23,33 @@
  * Escape characters as %XX sequences.
  * Return value: New string.
  */
-char *a_Misc_escape_chars(const char *str, const char *esc_set)
+std::string
+a_Misc_escape_chars( const std::string_view str,
+		const std::string_view esc_set )
 {
-   static const char hex[] = "0123456789ABCDEF";
-   char *p = NULL;
-   Dstr *dstr;
-   int i;
+	using namespace std::literals::string_view_literals;
 
-   dstr = dStr_sized_new(64);
-   for (i = 0; str[i]; ++i) {
-      if (str[i] <= 0x1F || str[i] == 0x7F || strchr(esc_set, str[i])) {
-         dStr_append_c(dstr, '%');
-         dStr_append_c(dstr, hex[(str[i] >> 4) & 15]);
-         dStr_append_c(dstr, hex[str[i] & 15]);
-      } else {
-         dStr_append_c(dstr, str[i]);
-      }
-   }
-   p = dstr->str;
-   dStr_free(dstr, FALSE);
+	const auto hex= "0123456789ABCDEF"sv;
 
-   return p;
+	std::string rv;
+	rv.reserve( 64 );
+
+
+	for( const char ch: str )
+	{
+		if( ch <= 0x1F or ch == 0x7F or esc_set.contains( ch ) )
+		{
+			rv+= '%';
+			rv+= hex[ ( ch >> 4 ) & 0xF ];
+			rv+= hex[ ch & 0xF ];
+		}
+		else
+		{
+			rv+= ch;
+		}
+	}
+
+	return rv;
 }
 
 #define TAB_SIZE 8
diff --git a/src/misc.hh b/src/misc.hh
index 18981ee..4cf853a 100644
--- a/src/misc.hh
+++ b/src/misc.hh
@@ -4,7 +4,12 @@
 
 #define d_isascii(c)  (((c) & ~0x7f) == 0) 
 
-char *a_Misc_escape_chars(const char *str, const char *esc_set);
+#ifdef __cplusplus
+#include <string>
+#include <string_view>
+std::string a_Misc_escape_chars(std::string_view str, std::string_view esc_set);
+#endif
+
 int a_Misc_expand_tabs(char **start, char *end, char *buf, int buflen);
 int a_Misc_get_content_type_from_data(void *Data, size_t Size,const char **PT);
 int a_Misc_content_type_check(const char *EntryType, const char *DetectedType);
diff --git a/src/uicmd.cc b/src/uicmd.cc
index d9affad..b92742c 100644
--- a/src/uicmd.cc
+++ b/src/uicmd.cc
@@ -1152,16 +1152,14 @@ void a_UIcmd_tools(void *vbw, int x, int y)
  */
 void a_UIcmd_open_file(void *vbw)
 {
-   char *name;
    DilloUrl *url;
 
-   name = a_Dialog_open_file("Flenser: Open File", NULL, "");
+   auto name = a_Dialog_open_file("Flenser: Open File", std::nullopt, "");
 
-   if (name) {
-      url = a_Url_new(name, "file:");
+   if (name.has_value()) {
+      url = a_Url_new(name.value().c_str(), "file:");
       a_UIcmd_open_url((BrowserWindow*)vbw, url);
       a_Url_free(url);
-      dFree(name);
    }
 }