Updated Linux/UNIX port to use XDG_CONFIG_HOME for storing settings

file.  For most people, that means the files are now stored in
'~/.config/stella' instead of '~/.stella'.  Manually moving the directory
will be necessary if you wish to keep the old settings.

Changes.txt

@@ -14,6 +14,17 @@
 
 4.7.3 to 5.0: (xxx. xx, 2017)
 
+  * For the Linux/UNIX port:
+    - The settings directory now uses the XDG Base Directory Specification.
+      In most cases, this means that your files will now be stored in
+      '~/.config/stella' instead of '~/.stella'.  To keep your old settings,
+      run the following commands from the terminal:
+        cd ~
+        mv .stella .config/stella
+
+      You will probably need to edit '~/.config/stella/stellarc' and change
+      some paths accordingly.
+
   * For the OSX port:
     - Always use the built-in zlib library instead of the system version.
 
@@ -23,6 +34,7 @@
         cd ~/Library/Preferences
         mv net.sourceforge.Stella.plist Stella-emu.plist
 
+  * Updated included PNG and ZLIB libraries to latest stable version.
 
 -Have fun!
 

docs/index.html

@@ -2963,7 +2963,7 @@
   <p><table cellpadding="5" border="1">
     <tr>
       <td><b>Linux/Unix</b></td>
-      <td><i>$HOME/.stella/stellarc</i></td>
+      <td><i>$HOME/.config/stella/stellarc</i></td>
     </tr>
     <tr>
       <td><b>Macintosh</b></td>
@@ -3062,7 +3062,7 @@ Ms Pac-Man (Stella extended codes):
   <p><table cellpadding="5" border="1">
     <tr>
       <td><b>Linux/Unix</b></td>
-      <td><i>$HOME/.stella/stella.cht</i></td>
+      <td><i>$HOME/.config/stella/stella.cht</i></td>
     </tr>
     <tr>
       <td><b>Macintosh</b></td>
@@ -3396,7 +3396,7 @@ Ms Pac-Man (Stella extended codes):
   <p><table cellpadding="5" border="1">
     <tr>
       <td><b>Linux/Unix</b></td>
-      <td><i>$HOME/.stella/stella.pro</i></td>
+      <td><i>$HOME/.config/stella/stella.pro</i></td>
     </tr>
     <tr>
       <td><b>Macintosh</b></td>
@@ -3461,7 +3461,7 @@ Ms Pac-Man (Stella extended codes):
   <p><table cellpadding="5" border="1">
     <tr>
       <td><b>Linux/Unix</b></td>
-      <td><i>$HOME/.stella/stella.pal</i></td>
+      <td><i>$HOME/.config/stella/stella.pal</i></td>
     </tr>
     <tr>
       <td><b>Macintosh</b></td>

src/unix/OSystemUNIX.cxx

@@ -15,6 +15,8 @@
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //============================================================================
 
+#include <cstdlib>
+
 #include "OSystemUNIX.hxx"
 
 /**
@@ -31,6 +33,12 @@
 OSystemUNIX::OSystemUNIX()
   : OSystem()
 {
-  setBaseDir("~/.stella");
-  setConfigFile("~/.stella/stellarc");
+  // Use XDG_CONFIG_HOME if defined, otherwise use the default
+  const char* configDir = getenv("XDG_CONFIG_HOME");
+  if(configDir == NULL)  configDir = "~/.config";
+
+  string stellaDir = string(configDir) + "/stella";
+
+  setBaseDir(stellaDir);
+  setConfigFile(stellaDir + "/stellarc");
 }