Fix name clash with zlib gzopen on (64-bit) Linux.

Compilation error message:

src/Fl_SVG_Image.cxx:80:21: error: out-of-line definition of 'gzopen64' does
not match any declaration in 'Fl_SVG_Image'; did you mean 'gzopen'?
void* Fl_SVG_Image::gzopen(const char *fname) {
                    ^~~~~~
                    gzopen
/usr/include/zlib.h:1709:20: note: expanded from macro 'gzopen'
#    define gzopen gzopen64
                   ^

The culprit was the macro defined in zlib.h (above).


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12479 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/Fl_SVG_Image.H

@@ -74,7 +74,7 @@ public:
   virtual void color_average(Fl_Color c, float i);
   virtual void draw(int X, int Y, int W, int H, int cx = 0, int cy = 0);
   void draw(int X, int Y) { draw(X, Y, w(), h(), 0, 0); }
-  static void* gzopen(const char *fname);
+  static void* fl_gzopen(const char *fname);
 };
 
 #endif // FL_SVG_IMAGE_H

src/Fl_SVG_Image.cxx

@@ -77,7 +77,7 @@ float Fl_SVG_Image::svg_scaling_(int W, int H) {
 }
 
 /** Opens for reading a potentially gzip'ed file identified by a UTF-8 encoded filename. */
-void* Fl_SVG_Image::gzopen(const char *fname) {
+void* Fl_SVG_Image::fl_gzopen(const char *fname) {
 #if defined(HAVE_LIBZ)
 #  ifdef _WIN32
   unsigned wl = fl_utf8towc(fname, strlen(fname), NULL, 0) + 1;
@@ -102,7 +102,7 @@ static char *svg_inflate(const char *fname) {
   struct stat b;
   fl_stat(fname, &b);
   long size = b.st_size;
-  gzFile gzf = (gzFile)Fl_SVG_Image::gzopen(fname);
+  gzFile gzf = (gzFile)Fl_SVG_Image::fl_gzopen(fname);
   if (!gzf) return NULL;
   int l;
   bool direct = gzdirect(gzf);

src/fl_images_core.cxx

@@ -94,7 +94,7 @@ fl_check_images(const char *name,		// I - Filename
 #ifdef FLTK_USE_NANOSVG
 #  if defined(HAVE_LIBZ)
   if (header[0] == 0x1f && header[1] == 0x8b) { // denotes gzip'ed data
-    gzFile gzf = (gzFile)Fl_SVG_Image::gzopen(name);
+    gzFile gzf = (gzFile)Fl_SVG_Image::fl_gzopen(name);
     if (gzf) {
       gzread(gzf, header, headerlen);
       gzclose(gzf);