Fix compilation on old gcc (#606)

* Fixing char* use in FLUID
* Fixing const cast

FL/Fl_String.H

@@ -91,7 +91,7 @@ public:
 
 private:
   void init();
-  void alloc_buf(int size);
+  void alloc_buf(int size, bool preserve_text=false);
   void release();
 
 public:
@@ -99,10 +99,12 @@ public:
   void value(const char *str, int slen);
 
   const char *value() const { return value_; }
+  char *buffer() { return value_; }
   int size() const { return size_; }
 
   int slen() const;
   int capacity() const;
+  void capacity(int num_bytes);
 
   void debug(const char *info = 0) const;     // output string info
   void hexdump(const char *info = 0) const;   // output string info + hexdump

fluid/code.cxx

@@ -612,7 +612,7 @@ int write_code(const char *s, const char *t) {
         write_c("// Initialize I18N stuff now for menus...\n");
         write_c("#%sinclude <locale.h>\n", indent());
         write_c("static char *_locale = setlocale(LC_MESSAGES, \"\");\n");
-        write_c("static nl_catd _catalog = catopen(\"%s\", 0);\n", P.i18n_program);
+        write_c("static nl_catd _catalog = catopen(\"%s\", 0);\n", P.i18n_program.value());
       }
     }
     if (conditional) {

fluid/fluid.cxx

@@ -254,7 +254,6 @@ Project P;
 
 Project::Project() :
   i18n_type(0),
-  i18n_program(""),
   include_H_from_C(1),
   use_FL_COMMAND(0),
   utf8_in_src(0),
@@ -277,7 +276,7 @@ void Project::reset() {
   i18n_static_function = "";
   i18n_file = "";
   i18n_set = "";
-  i18n_program[0] = 0;
+  i18n_program = "";
   include_H_from_C = 1;
   use_FL_COMMAND = 0;
   utf8_in_src = 0;
@@ -998,8 +997,9 @@ int write_code_files() {
   }
   char cname[FL_PATH_MAX+1];
   char hname[FL_PATH_MAX+1];
-  strlcpy(P.i18n_program, fl_filename_name(filename), FL_PATH_MAX);
-  fl_filename_setext(P.i18n_program, FL_PATH_MAX, "");
+  P.i18n_program = fl_filename_name(filename);
+  P.i18n_program.capacity(FL_PATH_MAX);
+  fl_filename_setext(P.i18n_program.buffer(), FL_PATH_MAX, "");
   if (P.code_file_name[0] == '.' && strchr(P.code_file_name, '/') == NULL) {
     strlcpy(cname, fl_filename_name(filename), FL_PATH_MAX);
     fl_filename_setext(cname, FL_PATH_MAX, P.code_file_name);
@@ -1878,8 +1878,9 @@ void update_sourceview_cb(Fl_Button*, void*)
     sv_strings->buffer()->loadfile(fn);
     sv_strings->scroll(top, 0);
   } else if (sv_source->visible_r() || sv_header->visible_r()) {
-    strlcpy(P.i18n_program, fl_filename_name(sv_source_filename), FL_PATH_MAX);
-    fl_filename_setext(P.i18n_program, FL_PATH_MAX, "");
+    P.i18n_program = fl_filename_name(sv_source_filename);
+    P.i18n_program.capacity(FL_PATH_MAX);
+    fl_filename_setext(P.i18n_program.buffer(), FL_PATH_MAX, "");
     Fd_String code_file_name_bak = P.code_file_name;
     P.code_file_name = sv_source_filename;
     Fd_String header_file_name_bak = P.header_file_name;

fluid/fluid.h

@@ -105,7 +105,7 @@ public:
   Fd_String i18n_static_function;
   Fd_String i18n_file;
   Fd_String i18n_set;
-  char i18n_program[FL_PATH_MAX+1];
+  Fd_String i18n_program;
   int include_H_from_C;
   int use_FL_COMMAND;
   int utf8_in_src;

src/Fl_JPEG_Image.cxx

@@ -304,7 +304,7 @@ void Fl_JPEG_Image::load_jpg_(const char *filename, const char *sharename, const
     if (data_length==-1)
       jpeg_unprotected_mem_src(&dinfo, data);
     else
-      jpeg_mem_src(&dinfo, data, (size_t)data_length);
+      jpeg_mem_src(&dinfo, const_cast<unsigned char*>data, (size_t)data_length);
   }
   jpeg_read_header(&dinfo, TRUE);
 

src/Fl_String.cxx

@@ -69,7 +69,12 @@ Fl_String::~Fl_String() {
   delete[] value_;
 }
 
-void Fl_String::alloc_buf(int size) {
+/** Grow the buffer size to at least size+1 bytes.
+ By default, this call destroys the contents of the current buffer.
+ \param size in bytes
+ \param preserve_text copy existing text into the new buffer
+ */
+void Fl_String::alloc_buf(int size, bool preserve_text) {
   if (size < 0)
     return;
   if (size > 0 && size <= capacity_)
@@ -79,7 +84,14 @@ void Fl_String::alloc_buf(int size) {
   char *new_value = new char[new_size];
   capacity_ = new_size - 1;
 
-  size_ = 0;
+  if (preserve_text) {
+    size_ = (int)strlen(value_);
+    // the new buffer always has a higher capacity than the old one
+    // make sure we copy the trailing NUL.
+    memcpy(new_value, value_, size_+1);
+  } else {
+    size_ = 0;
+  }
   delete[] value_;
   value_ = new_value;
 }
@@ -111,6 +123,15 @@ int Fl_String::capacity() const {
   return capacity_; // > 0 ? capacity_ - 1 : capacity_;
 }
 
+/** Set the minumum capacity to num_bytes plus one for a terminating NUL.
+ The cintents of the string buffer will be copied if needed.
+ \param num_bytes minimum size of buffer
+ */
+void Fl_String::capacity(int num_bytes) {
+  alloc_buf(num_bytes, true);
+}
+
+
 void Fl_String::release() {
   delete[] value_;
   value_ = 0;