Fixed crash in Fl_Preferences if 2nd or 3rd argument in the 'path' co…

…nstructor were NULL

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@5007 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

CHANGES

@@ -1,9 +1,6 @@
-CHANGES IN FLTK 1.1.9
-
-	- caret key lookup was missing for OS X
-
 CHANGES IN FLTK 1.1.8
 
+	- caret key lookup was missing for OS X
 	- FLUID didn't handle loading .fl files with
 	  international characters properly with all compilers
 	  (STR #1150)

documentation/Fl_Preferences.html

@@ -69,9 +69,11 @@ <h3>Methods</h3>
 
 </ul>
 
-<H4><a name="Fl_Preferences.Fl_Preferences">Fl_Preferences(enum Root root,
-const char *vendor, const char *application)<BR>
-Fl_Preferences(Fl_Preferences &amp;p, const char *groupname)</a></H4>
+<H4><a name="Fl_Preferences.Fl_Preferences">
+Fl_Preferences(enum Root root, const char *vendor, const char *application)<BR>
+Fl_Preferences(const char *path, const char *vendor, const char *application)<BR>
+Fl_Preferences(Fl_Preferences &amp;p, const char *groupname)<BR>
+</a></H4>
 
 <P>The constructor creates a group that manages name/value pairs and
 child groups. Groups are ready for reading and writing at any time.
@@ -89,9 +91,15 @@ <H4><a name="Fl_Preferences.Fl_Preferences">Fl_Preferences(enum Root root,
 <tt>application</tt> must be valid relative UNIX pathnames and
 may contain '/'s to create deeper file structures.
 
-<P>The <tt>groupname</tt> argument identifies a group of
-entries. It can contain '/'s to get quick access to individual
-elements inside the hierarchy.
+<P>The second format is used to create a preferences file at an
+arbitrary position in the file system. The file name is generated
+as <tt><i>path</i>/<i>application</i>.prefs</tt>. If <i>application</i>
+is 0, <i>path</i> must contain the full file name.
+
+<P>The third format generates a new group of preference entries
+inside the group or file <i>p</i>. The <tt>groupname</tt> argument 
+identifies a group of entries. It can contain '/'s to get quick 
+access to individual elements inside the hierarchy.
 
 <H4><a name="Fl_Preferences.~Fl_Preferences">~Fl_Preferences()</a></H4>
 

src/Fl_Preferences.cxx

@@ -693,12 +693,17 @@ Fl_Preferences::RootNode::RootNode( Fl_Preferences *prefs, Root root, const char
 // - construct the name of the file that will hold our preferences
 Fl_Preferences::RootNode::RootNode( Fl_Preferences *prefs, const char *path, const char *vendor, const char *application )
 {
-  char filename[ FL_PATH_MAX ]; filename[0] = 0;
-
-  snprintf(filename, sizeof(filename), "%s/%s.prefs", path, application);
-
+  if (!vendor)
+    vendor = "unknown";
+  if (!application) {
+    application = "unknown";
+    filename_ = strdup(path);
+  } else {
+    char filename[ FL_PATH_MAX ]; filename[0] = 0;
+    snprintf(filename, sizeof(filename), "%s/%s.prefs", path, application);
+    filename_  = strdup(filename);
+  }
   prefs_       = prefs;
-  filename_    = strdup(filename);
   vendor_      = strdup(vendor);
   application_ = strdup(application);