Correctly compute the length of the path (including systems where the delimitator

is not just one char) and use the computed length. Handle Windows paths as they
don't have to start with /.

This commit was SVN r8744.

opal/util/os_path.c

@@ -64,7 +64,7 @@ char *opal_os_path(bool relative, ...)
 
     if (0 == num_elements) { /* must be looking for a simple answer */
     	path = (char *)malloc(3);
-            path[0] = '\0';
+        path[0] = '\0';
     	if (relative) {
     	    strcpy(path, ".");
             strcat(path, path_sep);
@@ -79,21 +79,30 @@ char *opal_os_path(bool relative, ...)
 
     /* setup path with enough room for the string terminator, the elements, and
        the separator between each of the elements */
-    total_length = total_length + num_elements + 1;
+    total_length = total_length + num_elements * strlen(path_sep) + 1;
     if (total_length > MAXPATHLEN) {  /* path length is too long - reject it */
     	return(NULL);
     }
 
-    path = (char *)malloc(2 + total_length + num_elements-1);
+    path = (char *)malloc(total_length);
     if (NULL == path) {
-	   return(NULL);
+        return(NULL);
     }
     path[0] = 0;
 
     if (relative) {
-	   strcpy(path, ".");
+        strcpy(path, ".");
     }
 
+    /* Windows does not require to have the initial separator. */
+    if( NULL != (element=va_arg(ap1, char*)) ) {
+#ifndef __WINDOWS__
+    	if (path_sep[0] != element[0]) {
+            strcat(path, path_sep);
+        }
+#endif  /* __WINDOWS__ */
+        strcat(path, element);
+    }
     while (NULL != (element=va_arg(ap1, char*))) {
     	if (path_sep[0] != element[0]) {
             strcat(path, path_sep);