diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c3f8de6ba29..b194fe902fe 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2000-02-21  Gabriel Dos Reis  <gdr@codesourcery.com>
+
+	* diagnostic.c (init_output_buffer): Make it possible to output at
+	least 32 characters if we're given a too long prefix.
+
 2000-02-20  Mark Mitchell  <mark@codesourcery.com>
 
 	* varasm.c (initializer_constant_valid_p): Call
diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c
index 4aa084b379b..2af8e125fc7 100644
--- a/gcc/diagnostic.c
+++ b/gcc/diagnostic.c
@@ -152,10 +152,17 @@ init_output_buffer (buffer, prefix, max_length)
      char *prefix;
      int max_length;
 {
+  int prefix_length = strlen (prefix);
+
   obstack_init (&buffer->obstack);
   buffer->prefix = prefix;
   buffer->line_length = 0;
-  buffer->max_length = max_length;
+  /* If the prefix is ridiculously too long, output at least
+     32 characters.  */
+  if (max_length - prefix_length < 32)
+    buffer->max_length = max_length + 32;
+  else
+    buffer->max_length = max_length;
 }
 
 /* Return BUFFER's prefix.  */