diff -Nru groff-1.20.1/src/devices/grohtml/post-html.cpp new/src/devices/grohtml/post-html.cpp
--- groff-1.20.1/src/devices/grohtml/post-html.cpp	2009-01-09 12:25:52.000000000 -0200
+++ new/src/devices/grohtml/post-html.cpp	2009-10-30 18:02:18.000000000 -0200
@@ -1588,7 +1588,7 @@
 
 	  buffer += as_string(h);
 	  buffer += '\0';
-	  fprintf(f, buffer.contents());
+	  fprintf(f, "%s", buffer.contents());
 	} else
 	  fputs(g->text_string, f);
 	h++;
diff -Nru groff-1.20.1/src/roff/troff/node.cpp new/src/roff/troff/node.cpp
--- groff-1.20.1/src/roff/troff/node.cpp	2009-01-09 12:25:52.000000000 -0200
+++ new/src/roff/troff/node.cpp	2009-10-30 17:58:51.000000000 -0200
@@ -2196,7 +2196,7 @@
   if (c)
     fprintf(stderr, "%c", c);
   else
-    fprintf(stderr, ci->nm.contents());
+    fprintf(stderr, "%s", ci->nm.contents());
   if (push_state)
     fprintf(stderr, " <push_state>");
   if (state)
diff -Nru groff-1.20.1/src/utils/hpftodit/hpftodit.cpp new/src/utils/hpftodit/hpftodit.cpp
--- groff-1.20.1/src/utils/hpftodit/hpftodit.cpp	2009-01-09 12:25:52.000000000 -0200
+++ new/src/utils/hpftodit/hpftodit.cpp	2009-10-30 18:05:13.000000000 -0200
@@ -870,9 +870,9 @@
       else if (!all_flag)
 	continue;
       else if (tfm_type == MSL)
-	printf(hp_msl_to_ucode_name(charcode));
+	printf("%s", hp_msl_to_ucode_name(charcode));
       else
-	printf(unicode_to_ucode_name(charcode));
+	printf("%s", unicode_to_ucode_name(charcode));
 
       printf("\t%d,%d",
 	     scale(char_table[i].width), scale(char_table[i].ascent));