Index: xc/programs/xrdb/xrdb.c
===================================================================
RCS file: /cvs/xorg/xc/programs/xrdb/xrdb.c,v
retrieving revision 1.2
diff -u -r1.2 xrdb.c
--- xc/programs/xrdb/xrdb.c	23 Apr 2004 19:55:03 -0000	1.2
+++ xc/programs/xrdb/xrdb.c	31 Aug 2005 23:10:42 -0000
@@ -67,6 +67,9 @@
 #endif /* __UNIXOS2__ */
 #endif /* CPP */
 
+/* A list of C preprocessor programs to try before falling back to CPP */
+char *preferred_cpps[] = { "mcpp" };
+
 #define INIT_BUFFER_SIZE 10000
 #define INIT_ENTRY_SIZE 500
 
@@ -120,7 +123,7 @@
 #endif
 int oper = OPLOAD;
 char *editFile = NULL;
-char *cpp_program = CPP;
+char *cpp_program;
 char *backup_suffix = BACKUP_SUFFIX;
 Bool dont_execute = False;
 String defines;
@@ -767,6 +770,63 @@
     arg->used += strlen(s);
 }   
 
+static char *
+find_program(char *progname)
+{
+    static char *progpath = NULL;
+    char *path;
+    size_t len;
+
+    if(progpath != NULL)
+        free(progpath);
+
+    path = getenv("PATH");
+
+    progpath = malloc(strlen(path) + strlen(progname) + 2);
+    if(!progpath)
+	    fatal("%s: Not enough memory\n", ProgramName);
+
+    while(path && *path)
+    {
+        len = strcspn(path, ":");
+        if(len > 0)
+        {
+            strncpy(progpath, path, len);
+            progpath[len] = '\0';
+            strcat(progpath, "/");
+            strcat(progpath, progname);
+
+            if(access(progpath, X_OK) == 0)
+                return progpath;
+        }
+
+        path += len;
+        if(*path)
+            path++;
+    }
+
+    return NULL;
+}
+
+static char*
+find_cpp(void)
+{
+    char progname[sizeof(preferred_cpps[0])];
+    int i;
+    size_t len;
+
+    for(i = 0; i < sizeof(preferred_cpps) / sizeof(preferred_cpps[0]) ; i++)
+    {
+        len = strcspn(preferred_cpps[i], " ");
+        strncpy(progname, preferred_cpps[i], len);
+        progname[len] = '\0';
+
+        if(find_program(progname))
+            return preferred_cpps[i];
+    }
+
+    return CPP;
+}
 
 int
 main(int argc, char *argv[])
@@ -785,6 +845,8 @@
     /* initialize the includes String struct */
     addstring(&includes, "");
 
+    cpp_program = find_cpp();
+
     /* needs to be replaced with XrmParseCommand */
 
     for (i = 1; i < argc; i++) {