Index: src/printf.c
==================================================================
--- src/printf.c
+++ src/printf.c
@@ -11,10 +11,25 @@
 ** routines format strings much like the printf() from the standard C
 ** library, though the implementation here has enhancements to support
 ** SQLlite.
 */
 #include "sqliteInt.h"
+
+/*
+** If the strchrnul() library function is available, then set
+** HAVE_STRCHRNUL.  If that routine is not available, this module
+** will supply its own.  The built-in version is slower than
+** the glibc version so the glibc version is definitely preferred.
+*/
+#if !defined(HAVE_STRCHRNUL)
+# if defined(__linux__) && defined(_GNU_SOURCE)
+#  define HAVE_STRCHRNUL 1
+# else
+#  define HAVE_STRCHRNUL 0
+# endif
+#endif
+
 
 /*
 ** Conversion types fall into various categories as defined by the
 ** following enumeration.
 */
@@ -222,13 +237,17 @@
     bArgList = useIntern = 0;
   }
   for(; (c=(*fmt))!=0; ++fmt){
     if( c!='%' ){
       bufpt = (char *)fmt;
-      while( (c=(*++fmt))!='%' && c!=0 ){};
+#if HAVE_STRCHRNUL
+      fmt = strchrnul(fmt, '%');
+#else
+      do{ fmt++; }while( *fmt && *fmt != '%' );
+#endif
       sqlite3StrAccumAppend(pAccum, bufpt, (int)(fmt - bufpt));
-      if( c==0 ) break;
+      if( *fmt==0 ) break;
     }
     if( (c=(*++fmt))==0 ){
       sqlite3StrAccumAppend(pAccum, "%", 1);
       break;
     }