patch 7.4.2067
Problem:    Compiler warning for char/char_u conversion. (Tony Mechelynck)
            Inefficient code.
Solution:   Use more lines to fill with spaces. (Nikolai Pavlov) Add type cast.
diff --git a/src/quickfix.c b/src/quickfix.c
index 3794e6a..fecc2c9 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -2593,9 +2593,14 @@
 
     if (title != NULL)
     {
-	while (STRLEN(buf) < 34)
-	    STRCAT(buf, " ");
-	vim_strcat(buf, title, IOSIZE);
+	size_t	len = STRLEN(buf);
+
+	if (len < 34)
+	{
+	    vim_memset(buf + len, ' ', 34 - len);
+	    buf[34] = NUL;
+	}
+	vim_strcat(buf, (char_u *)title, IOSIZE);
     }
     trunc_string(buf, buf, Columns - 1, IOSIZE);
     msg(buf);