Cygwin/X: Improve XWinrc loading and error recovery

If $HOME/.XWinrc is present but badly formed, ignore it and try
system.XWinrc instead.  If neither file is present or both are badly
formed, provide a built-in default which gives the user the chance to
load their new or fixed configuration without restarting.

Signed-off-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net>

2 files changed, 65 insertions, 19 deletions

diff --git a/hw/xwin/winprefs.c b/hw/xwin/winprefs.c
index c4a71a9ac..0823f3fab 100644
--- a/hw/xwin/winprefs.c
+++ b/hw/xwin/winprefs.c
@@ -51,8 +51,8 @@
 
 extern const char *winGetBaseDir(void);
 
-/* From winmultiwindowflex.l, the real parser */
-extern void parse_file (FILE *fp);
+/* From winprefslex.l, the real parser */
+extern int parse_file (FILE *fp);
 
 
 /* Currently in use command ID, incremented each new menu item created */
@@ -706,6 +706,54 @@ winIconIsOverride(unsigned hiconIn)
 
 
 /*
+ * Open and parse the XWinrc config file @path.
+ * If @path is NULL, use the built-in default.
+ */
+static int
+winPrefsLoadPreferences (char *path)
+{
+  FILE *prefFile = NULL;
+
+  if (path)
+    prefFile = fopen (path, "r");
+  else
+    {
+      char defaultPrefs[] =
+        "MENU rmenu {\n"
+        "  \"How to customize this menu\" EXEC \"xterm +tb -e man XWinrc\"\n"
+        "  \"Launch xterm\" EXEC xterm\n"
+        "  \"Load .XWinrc\" RELOAD\n"
+        "  SEPARATOR\n"
+        "}\n"
+        "\n"
+        "ROOTMENU rmenu\n";
+
+      path = "built-in default";
+      prefFile = fmemopen(defaultPrefs, strlen(defaultPrefs), "r");
+    }
+
+  if (!prefFile)
+    {
+      ErrorF ("LoadPreferences: %s not found\n", path);
+      return FALSE;
+    }
+
+  ErrorF ("LoadPreferences: Loading %s\n", path);
+
+  if((parse_file (prefFile)) != 0)
+    {
+      ErrorF ("LoadPreferences: %s is badly formed!\n", path);
+      fclose (prefFile);
+      return FALSE;
+    }
+
+  fclose (prefFile);
+  return TRUE;
+}
+
+
+
+/*
  * Try and open ~/.XWinrc and system.XWinrc
  * Load it into prefs structure for use by other functions
  */
@@ -714,16 +762,15 @@ LoadPreferences (void)
 {
   char *home;
   char fname[PATH_MAX+NAME_MAX+2];
-  FILE *prefFile;
   char szDisplay[512];
   char *szEnvDisplay;
   int i, j;
   char param[PARAM_MAX+1];
   char *srcParam, *dstParam;
+  int parsed = FALSE;
 
   /* First, clear all preference settings */
   memset (&pref, 0, sizeof(pref));
-  prefFile = NULL;
 
   /* Now try and find a ~/.xwinrc file */
   home = getenv ("HOME");
@@ -733,14 +780,11 @@ LoadPreferences (void)
       if (fname[strlen(fname)-1]!='/')
 	strcat (fname, "/");
       strcat (fname, ".XWinrc");
-      
-      prefFile = fopen (fname, "r");
-      if (prefFile)
-	ErrorF ("winPrefsLoadPreferences: %s\n", fname);
+      parsed = winPrefsLoadPreferences(fname);
     }
 
   /* No home file found, check system default */
-  if (!prefFile)
+  if (!parsed)
     {
       char buffer[MAX_PATH];
 #ifdef RELOCATE_PROJECTROOT
@@ -749,16 +793,14 @@ LoadPreferences (void)
       strncpy(buffer, SYSCONFDIR"/X11/system.XWinrc", sizeof(buffer));
 #endif
       buffer[sizeof(buffer)-1] = 0;
-      prefFile = fopen (buffer, "r");
-      if (prefFile)
-	ErrorF ("winPrefsLoadPreferences: %s\n", buffer);
+      parsed = winPrefsLoadPreferences(buffer);
     }
 
-  /* If we could open it, then read the settings and close it */
-  if (prefFile)
+  /* Neither user nor system configuration found, or were badly formed */
+  if (!parsed)
     {
-      parse_file (prefFile);
-      fclose (prefFile);
+      ErrorF ("LoadPreferences: See \"man XWinrc\" to customize the XWin menu.\n");
+      parsed = winPrefsLoadPreferences(NULL);
     }
 
   /* Setup a DISPLAY environment variable, need to allocate on heap */
diff --git a/hw/xwin/winprefslex.l b/hw/xwin/winprefslex.l
index 463dff4ca..ba8aea696 100644
--- a/hw/xwin/winprefslex.l
+++ b/hw/xwin/winprefslex.l
@@ -113,14 +113,18 @@ yywrap (void)
 /*
  * Run a file through the yacc parser
  */
-void
+int
 parse_file (FILE *file)
 {
+  int ret;
+
   if (!file)
-    return; 
+    return 1;
   
   yylineno = 1;
   yyin = file;
-  yyparse ();
+  ret = yyparse ();
+  yylex_destroy ();
+  return ret;
 }