fix in ZFont crash when drawing empty string

changelog.txt

@@ -1,5 +1,5 @@
 ZEngine Version Log for Version 0.8.5
-$Id: changelog.txt,v 1.51 2003/10/03 21:54:42 cozman Exp $
+$Id: changelog.txt,v 1.52 2003/10/05 19:59:29 cozman Exp $
 
 Changes are marked with symbols that describe them:
 ! is code that breaks backwards compatibility (used after 0.8.0-rc1, previous versions broke compatibility)
@@ -24,6 +24,7 @@ Changes are marked with symbols that describe them:
     - Removal of VC6 project files and official support.
     - Removal of SDL_net support in favour of external library.
     # Sweep of non-used legacy code.
+    # Fix crash in drawing blank string with ZFont.
     # Tests modified to show off loading of compressed files.
     # Moved image,sound,music and font loading code from legacy ZEngine location to respective classes.
     # Tiny optimizations within newer ZImage code.

src/ZE_ZFont.cpp

@@ -13,7 +13,7 @@
     \brief Source file for ZFont.
 
     Implementation of ZFont, the basic Font class for ZEngine.
-    <br>$Id: ZE_ZFont.cpp,v 1.13 2003/09/24 02:03:18 cozman Exp $<br>
+    <br>$Id: ZE_ZFont.cpp,v 1.14 2003/10/05 19:59:29 cozman Exp $<br>
     \author James Turk
 **/
 
@@ -85,12 +85,16 @@ void ZFont::Release()
 
 void ZFont::DrawText(std::string text, ZImage &image) const
 {
+    if(text.length() == 0)
+        text = " ";
     image.Attach(TTF_RenderText_Blended(rFont, text.c_str(), rColor));
     image.SetAlpha(rColor.unused);  //the images alpha comes from the SetColor a parameter
 }
 
 void ZFont::DrawShadedText(std::string text, ZImage &image) const
 {
+    if(text.length() == 0)
+        text = " ";
     image.Attach(TTF_RenderText_Shaded(rFont, text.c_str(), rColor, rBGColor));
     image.SetAlpha(rColor.unused);  
 }