Fix for http://bugs.gentoo.org/109781

--- converter/other/tifftopnm.c
+++ converter/other/tifftopnm.c
@@ -108,6 +108,9 @@
     unsigned int option_def_index;
     unsigned int alpha_spec;
 
+    /* make sure we init in case some options werent provided */
+    cmdlineP->alphaFilename = NULL;
+
     MALLOCARRAY_NOFAIL(option_def, 100);
 
     opt.opt_table = option_def;