1 files changed, 36 insertions, 26 deletions

diff --git a/src/Fl_Native_File_Chooser_Kdialog.cxx b/src/Fl_Native_File_Chooser_Kdialog.cxx
index d0580162d..68cb4729e 100644
--- a/src/Fl_Native_File_Chooser_Kdialog.cxx
+++ b/src/Fl_Native_File_Chooser_Kdialog.cxx
@@ -73,7 +73,7 @@ static int fnfc_dispatch(int /*event*/, Fl_Window* /*win*/) {
 }
 
 
-void Fl_Kdialog_Native_File_Chooser_Driver::build_command(std::string& command) {
+void Fl_Kdialog_Native_File_Chooser_Driver::build_command(char *command, int maxlen) {
   const char *option;
   switch (_btype) {
     case Fl_Native_File_Chooser::BROWSE_DIRECTORY:
@@ -103,23 +103,21 @@ void Fl_Kdialog_Native_File_Chooser_Driver::build_command(std::string& command)
   }
 
   // Build command
-  command = "kdialog";
+  int pos = 0;
+  pos += snprintf(command + pos, maxlen - pos, "kdialog");
   if (_title) {
-    std::string quoted_title = _title; shell_quote(quoted_title);
-    command += " --title ";
-    command += quoted_title;
+    char quoted_title[FL_PATH_MAX];
+    shell_quote(_title, quoted_title, sizeof(quoted_title));
+    pos += snprintf(command + pos, maxlen - pos, " --title %s", quoted_title);
   }
-  command += " ";
-  command += option;
-  command += " ";
-  command += preset;
+  pos += snprintf(command + pos, maxlen - pos, " %s %s", option, preset);
   if (_parsedfilt) {
-    std::string quoted_filt = _parsedfilt; shell_quote(quoted_filt);     // NOTE: orig code used double quoting -erco 1/10/24
-    command += " ";
-    command += quoted_filt;
+    char quoted_filt[FL_PATH_MAX * 2];
+    shell_quote(_parsedfilt, quoted_filt, sizeof(quoted_filt));
+    pos += snprintf(command + pos, maxlen - pos, " %s", quoted_filt);
   }
-  command += " 2> /dev/null";   // get rid of stderr
-  // printf("command = %s\n", command.c_str());
+  snprintf(command + pos, maxlen - pos, " 2> /dev/null");
+  // printf("command = %s\n", command);
 }
 
 
@@ -146,10 +144,10 @@ int Fl_Kdialog_Native_File_Chooser_Driver::show() {
       return retval;
   }
 
-  std::string command;
-  build_command(command);
-  //fprintf(stderr, "DEBUG: POPEN: %s\n", command.c_str());
-  FILE *pipe = popen(command.c_str(), "r");
+  char command[FL_PATH_MAX * 4];
+  build_command(command, sizeof(command));
+  //fprintf(stderr, "DEBUG: POPEN: %s\n", command);
+  FILE *pipe = popen(command, "r");
   fnfc_pipe_struct data;
   data.all_files = NULL;
   if (pipe) {
@@ -307,17 +305,29 @@ const char *Fl_Kdialog_Native_File_Chooser_Driver::title() const {
   return _title;
 }
 
-// Add shell quotes around string 's'.
+// Add shell quotes around string 'in', store result in 'out'.
 // Handles quoting embedded quotes.
 //
-void Fl_Kdialog_Native_File_Chooser_Driver::shell_quote(std::string& s) {
-  std::string out = "'";                          // leading quote
-  for (int t=0; t<(int)s.size(); t++) {
-    if (s[t] == '\'') out += "'\"'\"'";         // quote any quotes
-    else              out += s[t];
+void Fl_Kdialog_Native_File_Chooser_Driver::shell_quote(const char *in, char *out, int maxlen) {
+  int pos = 0;
+  out[pos++] = '\'';                            // leading quote
+  while (*in && pos < maxlen - 6) {             // leave room for closing quote + null
+    if (*in == '\'') {
+      // quote any quotes: replace ' with '"'"'
+      if (pos + 5 < maxlen) {
+        out[pos++] = '\'';
+        out[pos++] = '"';
+        out[pos++] = '\'';
+        out[pos++] = '"';
+        out[pos++] = '\'';
+      }
+    } else {
+      out[pos++] = *in;
+    }
+    in++;
   }
-  out += "'";                                   // trailing quote
-  s = out;
+  out[pos++] = '\'';                            // trailing quote
+  out[pos] = '\0';
 }
 
 /**