Correct read/write incompatibility with compliant CDB files.

This fixes a bug introduced in 1.02 which accidentally changed
the hash algorithm due to a casting error.

Added xt tests to try to test binary regressions with 0.96 in
the future.

Fixes #12

Author: toddr

.github/workflows/testsuite.yml

@@ -30,6 +30,8 @@ jobs:
         run: perl -I$(pwd) Makefile.PL
       - name: make test
         run: make test
+      - name: Extended Tests
+        run: prove -b xt/*.t
 
   linux:
     name: "linux ${{ matrix.perl-version }}"
@@ -76,6 +78,8 @@ jobs:
       - run: perl Makefile.PL
       - run: make
       - run: make test
+      - name: Extended Tests
+        run: prove -b xt/*.t
 
   macOS:
     needs: [ubuntu, linux]
@@ -102,6 +106,8 @@ jobs:
       - run: perl Makefile.PL
       - run: make
       - run: make test
+      - name: Extended Tests
+        run: prove -b xt/*.t
 
   windows:
     needs: [ubuntu, linux]
@@ -126,3 +132,5 @@ jobs:
         run: make
       - name: Run Tests
         run: make test
+      - name: Extended Tests
+        run: prove -b xt/*.t

CDB_File.xs

@@ -188,7 +188,7 @@ static int cdb_make_addend(cdb_make *c, unsigned int keylen, unsigned int datale
 
 #define CDB_HASHSTART 5381
 
-#define cdb_hashadd(hh, cc) ((hh + (hh << 5)) ^ cc)
+#define cdb_hashadd(hh, cc) ((hh + (hh << 5)) ^ (unsigned char) cc)
 
 static U32 cdb_hash(char *buf, unsigned int len) {
 	U32 h;

Changelog

@@ -1,5 +1,9 @@
 Revision history for Perl extension CDB_File.
 
+1.03 - Todd Rinaldo <toddr@cpan.org> 2020-11-13
+     - Fix incompatibility with CDB files due to accidental algorithm change.
+     - Add xt tests for 0.96 databases to assure this does not happen again.
+
 1.02 - Todd Rinaldo <toddr@cpan.org> 2020-01-29
     - Invoke new as a class method in docs and practice.
     - Add support for COW PVs when returning key values. This will hopefully

xt/compatibility.cdb

@@ -0,0 +1,29 @@
+#!perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 304;
+
+use CDB_File ();
+
+my $file = 'xt/compatibility.cdb';
+our %cdb;
+tie %cdb, "CDB_File", $file;
+
+note "UTF8 test";
+my $utf8_key   = '“Copyright © ”';
+my $utf8_value = '“Trademark ™ ”';
+is( $cdb{$utf8_key}, $utf8_value, "UTF8 key fetches." );
+
+note "Random keys";
+my @keys = keys %cdb;
+
+my $empty_keys;
+foreach my $key (@keys) {
+    my $value = $cdb{$key};
+    isnt( $value, undef, "Fetched key isn't undef" );
+    $empty_keys++ if ( $value eq '' );
+}
+
+is( $empty_keys, 15, "15 of the keys were an empty string" );

xt/compatibility0.96.t

@@ -0,0 +1,42 @@
+#!perl
+
+use strict;
+use warnings;
+
+use blib;
+use CDB_File ();
+
+open( my $urand_fh, '<', '/dev/urandom' ) or die("Need /dev/urandom to run this utility");
+
+$CDB_File::VERSION eq '0.96' or die("This utility is meant to generate a CDB File on 0.96. You need to have that installed");
+
+my $file = 'xt/compatibility.cdb';
+
+my $utf8_key   = '“Copyright © ”';
+my $utf8_value = '“Trademark ™ ”';
+
+my $cdb_ver = $CDB_File::VERSION;
+
+unlink $file;
+my $cdb = CDB_File->new( $file, "$file.$$" ) or die $!;
+$cdb->insert( $utf8_key, $utf8_value );
+foreach my $step ( 1 .. 300 ) {
+    my $key   = rnd_str();
+    my $value = rnd_str();
+
+    # Inject a few values with an empty string.
+    $value = '' if ( $step % 20 == 0 );
+
+    $cdb->insert( $key, $value );
+}
+
+$cdb->insert( '', 'empty' );
+$cdb->finish;
+
+sub rnd_str {
+    my $len = int( rand(10) ) + 1;
+    my $buffer;
+    read( $urand_fh, $buffer, $len );
+
+    return $buffer;
+}