Index: ext/fts3/fts3_unicode.c
==================================================================
--- ext/fts3/fts3_unicode.c
+++ ext/fts3/fts3_unicode.c
@@ -199,10 +199,11 @@
     if( (zOut-pCsr->zToken)>=(pCsr->nAlloc-4) ){
       char *zNew = sqlite3_realloc(pCsr->zToken, pCsr->nAlloc+64);
       if( !zNew ) return SQLITE_NOMEM;
       zOut = &zNew[zOut - pCsr->zToken];
       pCsr->zToken = zNew;
+      pCsr->nAlloc += 64;
     }
 
     /* Write the folded case of the last character read to the output */
     zEnd = z;
     WRITE_UTF8(zOut, sqlite3FtsUnicodeTolower(iCode));

Index: ext/fts3/fts3_unicode2.c
==================================================================
--- ext/fts3/fts3_unicode2.c
+++ ext/fts3/fts3_unicode2.c
@@ -119,12 +119,17 @@
     0x07D108B6, 0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018,
     0x07D7EC46, 0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401,
     0x38008060, 0x380400F0, 0x3C000001, 0x3FFFF401, 0x40000001,
     0x43FFF401,
   };
+  static const unsigned int aAscii[4] = {
+    0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
+  };
 
-  if( c<(1<<22) ){
+  if( c<128 ){
+    return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
+  }else if( c<(1<<22) ){
     unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
     int iRes;
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
     int iLo = 0;
     while( iHi>=iLo ){
@@ -234,11 +239,13 @@
   int ret = c;
 
   assert( c>=0 );
   assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );
 
-  if( c<65536 ){
+  if( c<128 ){
+    if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');
+  }else if( c<65536 ){
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
     int iLo = 0;
     int iRes = -1;
 
     while( iHi>=iLo ){

Index: ext/fts3/unicode/mkunicode.tcl
==================================================================
--- ext/fts3/unicode/mkunicode.tcl
+++ ext/fts3/unicode/mkunicode.tcl
@@ -102,10 +102,31 @@
     incr i
   }
   puts ""
   puts "  \};"
 }
+
+proc an_print_ascii_bitmap {lRange} {
+  foreach range $lRange {
+    foreach {iFirst nRange} $range {}
+    for {set i $iFirst} {$i < ($iFirst+$nRange)} {incr i} {
+      if {$i<=127} { set a($i) 1 }
+    }
+  }
+
+  set aAscii [list 0 0 0 0]
+  foreach key [array names a] {
+    set idx [expr $key >> 5]
+    lset aAscii $idx [expr [lindex $aAscii $idx] | (1 << ($key&0x001F))]
+  }
+
+  puts "  static const unsigned int aAscii\[4\] = \{"
+  puts -nonewline "   "
+  foreach v $aAscii { puts -nonewline [format " 0x%08X," $v] }
+  puts ""
+  puts "  \};"
+}
 
 proc print_isalnum {zFunc lRange} {
   puts "/*"
   puts "** Return true if the argument corresponds to a unicode codepoint"
   puts "** classified as either a letter or a number. Otherwise false."
@@ -113,12 +134,15 @@
   puts "** The results are undefined if the value passed to this function"
   puts "** is less than zero."
   puts "*/"
   puts "int ${zFunc}\(int c)\{"
   an_print_range_array $lRange
+  an_print_ascii_bitmap $lRange
   puts {
-  if( c<(1<<22) ){
+  if( c<128 ){
+    return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
+  }else if( c<(1<<22) ){
     unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
     int iRes;
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
     int iLo = 0;
     while( iHi>=iLo ){
@@ -363,11 +387,13 @@
   int ret = c;
 
   assert( c>=0 );
   assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );
 
-  if( c<65536 ){
+  if( c<128 ){
+    if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');
+  }else if( c<65536 ){
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
     int iLo = 0;
     int iRes = -1;
 
     while( iHi>=iLo ){