local-test-sqlite3-delta-01/diff/ref.diff

diff --git a/ext/misc/base85.c b/ext/misc/base85.c
index e7ef0a04c..2859a9b62 100644
--- a/ext/misc/base85.c
+++ b/ext/misc/base85.c
@@ -170,6 +170,12 @@ static char *putcs(char *pc, char *s){
 static char* toBase85( u8 *pIn, int nbIn, char *pOut, char *pSep ){
   int nCol = 0;
   while( nbIn >= 4 ){
+    // Use the Adobe shortcut to encode a 32-bit 0 value quickly.
+    if( pIn[0] == 0x0 && pIn[1] == 0x0 && pIn[2] == 0x0 && pIn[3] == 0x0 ) {
+      pIn += 4;
+      *pOut++ = 'z';
+      continue;
+    }
     int nco = 5;
     unsigned long qbv = (((unsigned long)pIn[0])<<24) |
                         (pIn[1]<<16) | (pIn[2]<<8) | pIn[3];
@@ -212,6 +218,17 @@ static u8* fromBase85( char *pIn, int ncIn, u8 *pOut ){
   if( ncIn>0 && pIn[ncIn-1]=='\n' ) --ncIn;
   while( ncIn>0 ){
     static signed char nboi[] = { 0, 0, 1, 2, 3, 4 };
+    /* Enable use of the Adobe "z" extension, which
+    ** compresses four zero bytes into a single z character.
+    */
+    if( *pIn == 'z' ) {
+      pIn++;
+      *pOut++ = 0x0;
+      *pOut++ = 0x0;
+      *pOut++ = 0x0;
+      *pOut++ = 0x0;
+      continue;
+    }
     char *pUse = skipNonB85(pIn, ncIn);
     unsigned long qv = 0L;
     int nti, nbo;
diff --git a/test/base85.test b/test/base85.test
new file mode 100644
index 000000000..bb723b372
--- /dev/null
+++ b/test/base85.test
@@ -0,0 +1,24 @@
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix basexx
+
+if {[catch {load_static_extension db basexx} error]} {
+  puts "Skipping basexx tests, hit load error: $error"
+  finish_test; return
+}
+
+# Test the 'z' expansion functionality
+# (SQL-006)
+do_execsql_test basexx-z-test-1 {
+  select hex(base85('z'));
+} {00000000}
+
+do_execsql_test basexx-z-test-3 {
+  select hex(base85('KHkS=z0I1c-$6'));
+} {74657374000000002066740C65}
+
+do_execsql_test basexx-z-test-4 {
+  select hex(base85('KHkS=0I1c-$6'));
+} {746573742066740C65}
+
+finish_test
diff --git a/test/basexx1.test b/test/basexx1.test
index 947a5678f..9030b5191 100644
--- a/test/basexx1.test
+++ b/test/basexx1.test
@@ -152,4 +152,17 @@ do_execsql_test 117 {
   SELECT num FROM bs WHERE base85(base85(b))!=b;
 } {}
 
+# Test the 'z' expansion functionality
+do_execsql_test basexx-z-test-1 {
+  select hex(base85('z'));
+} {00000000}
+
+do_execsql_test basexx-z-test-3 {
+  select hex(base85('KHkS=z0I1c-$6'));
+} {74657374000000002066740C65}
+
+do_execsql_test basexx-z-test-4 {
+  select hex(base85('KHkS=0I1c-$6'));
+} {746573742066740C65}
+
 finish_test