The built-in substr() function applied to a BLOB counts bytes, not characters. (CVS 3997)

FossilOrigin-Name: 75d573080d03ee48fe88710f70c6875ff9cae19c

manifest

@@ -1,5 +1,5 @@
-C Make\ssure\sthe\sparser\saborts\squickly\sfollowing\sa\ssyntax\serror.\s(CVS\s3996)
-D 2007-05-15T00:09:13
+C The\sbuilt-in\ssubstr()\sfunction\sapplied\sto\sa\sBLOB\scounts\sbytes,\snot\scharacters.\s(CVS\s3997)
+D 2007-05-15T01:13:47
 F Makefile.in 87b200ad9970907f76df734d29dff3d294c10935
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -71,7 +71,7 @@ F src/date.c 6049db7d5a8fdf2c677ff7d58fa31d4f6593c988
 F src/delete.c 5c0d89b3ef7d48fe1f5124bfe8341f982747fe29
 F src/experimental.c 1b2d1a6cd62ecc39610e97670332ca073c50792b
 F src/expr.c bad06f783d2daf1884a922859c8e7427323e7dc3
-F src/func.c b6586f83c141859c103dd4954de66efc3fbd101b
+F src/func.c cdbe36f2a71b7e6835189414c2fb626a339e300f
 F src/hash.c 67b23e14f0257b69a3e8aa663e4eeadc1a2b6fd5
 F src/hash.h 1b3f7e2609141fd571f62199fc38687d262e9564
 F src/insert.c e595ca26805dfb3a9ebaabc28e7947c479f3b14d
@@ -347,6 +347,7 @@ F test/speed2.test 53177056baf6556dcbdcf032bbdfc41c1aa74ded
 F test/sqllimits1.test b15a5784e47199d68fa1182157ba7e790f467d9f
 F test/subquery.test ae324ee928c5fb463a3ce08a8860d6e7f1ca5797
 F test/subselect.test 974e87f8fc91c5f00dd565316d396a5a6c3106c4
+F test/substr.test 9f26cfca74397b26ab217fb838c3d0549eb4bcf3
 F test/sync.test d05397b8f89f423dd6dba528692019ab036bc1c3
 F test/table.test dbdfd06aef054ad5aed8e57a782137d57d5c5528
 F test/tableapi.test 036575a98dcce7c92e9f39056839bbad8a715412
@@ -468,7 +469,7 @@ F www/fullscanb.gif f7c94cb227f060511f8909e10f570157263e9a25
 F www/index-ex1-x-b.gif f9b1d85c3fa2435cf38b15970c7e3aa1edae23a3
 F www/index.tcl 8f500433525f34ef93427ba5f4f83fb5fde1e0e7
 F www/indirect1b1.gif adfca361d2df59e34f9c5cac52a670c2bfc303a1
-F www/lang.tcl 26a38c36ec6686aee0e46eeac90acb3aae373537
+F www/lang.tcl 8dde95ed76af71579a132c9bb730d3764056d3ff
 F www/lockingv3.tcl e52345bd20323bef6146bfce18ae0829b2b7c87d
 F www/mingw.tcl d96b451568c5d28545fefe0c80bee3431c73f69c
 F www/nulls.tcl ec35193f92485b87b90a994a01d0171b58823fcf
@@ -490,7 +491,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P af76928fc5891f9a222ac0c39f8b443a9707b9e3
-R 3e5c27a41d7feb2f3994d5008df8b7ba
+P d07cdd3c096c120d104ae13f7932c0a955324517
+R 2be0a4c9f659ac8ba502f4d27f744853
 U drh
-Z 9652c7d3c4c7e15de8852ab1114d57ec
+Z 429140db9719a9a8e8c56d1f7aa1fad7

manifest.uuid

@@ -1 +1 @@
-d07cdd3c096c120d104ae13f7932c0a955324517
+75d573080d03ee48fe88710f70c6875ff9cae19c

src/func.c

@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.155 2007/05/12 06:11:12 danielk1977 Exp $
+** $Id: func.c,v 1.156 2007/05/15 01:13:47 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -146,7 +146,14 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 }
 
 /*
-** Implementation of the substr() function
+** Implementation of the substr() function.
+**
+** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
+** p1 is 1-indexed.  So substr(x,1,1) returns the first character
+** of x.  If x is text, then we actually count UTF-8 characters.
+** If x is a blob, then we count bytes.
+**
+** If p1 is negative, then we begin abs(p1) from the end of x[].
 */
 static void substrFunc(
   sqlite3_context *context,
@@ -157,14 +164,22 @@ static void substrFunc(
   const unsigned char *z2;
   int i;
   int len;
+  int p0type;
   i64 p1, p2;
 
   assert( argc==3 );
+  p0type = sqlite3_value_type(argv[0]);
+  if( p0type==SQLITE_BLOB ){
+    len = sqlite3_value_bytes(argv[0]);
+    z = sqlite3_value_blob(argv[0]);
+    if( z==0 ) return;
+  }else{
     z = sqlite3_value_text(argv[0]);
     if( z==0 ) return;
+    for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z2)!=0x80 ) len++; }
+  }
   p1 = sqlite3_value_int(argv[1]);
   p2 = sqlite3_value_int(argv[2]);
-  for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z2)!=0x80 ) len++; }
   if( p1<0 ){
     p1 += len;
     if( p1<0 ){
@@ -177,6 +192,7 @@ static void substrFunc(
   if( p1+p2>len ){
     p2 = len-p1;
   }
+  if( p0type!=SQLITE_BLOB ){
     for(i=0; i<p1 && z[i]; i++){
       if( (z[i]&0xc0)==0x80 ) p1++;
     }
@@ -187,6 +203,10 @@ static void substrFunc(
     while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p2++; }
     if( p2<0 ) p2 = 0;
     sqlite3_result_text(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
+  }else{
+    if( p2<0 ) p2 = 0;
+    sqlite3_result_blob(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
+  }
 }
 
 /*

test/substr.test

@@ -0,0 +1,103 @@
+# 2007 May 14
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the built-in SUBSTR() functions.
+#
+# $Id: substr.test,v 1.1 2007/05/15 01:13:47 drh Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+# Create a table to work with.
+#
+execsql { 
+  CREATE TABLE t1(t text, b blob)
+}
+proc substr-test {id string i1 i2 result} {
+  db eval {
+    DELETE FROM t1;
+    INSERT INTO t1(t) VALUES($string)
+  }
+  do_test substr-$id.1 [subst {
+    execsql {
+      SELECT substr(t, $i1, $i2) FROM t1
+    }
+  }] [list $result]
+  set qstr '[string map {' ''} $string]'
+  do_test substr-$id.2 [subst {
+    execsql {
+      SELECT substr($qstr, $i1, $i2)
+    }
+  }] [list $result]
+}
+proc subblob-test {id hex i1 i2 hexresult} {
+  db eval "
+    DELETE FROM t1;
+    INSERT INTO t1(b) VALUES(x'$hex')
+  "
+  do_test substr-$id.1 [subst {
+    execsql {
+      SELECT hex(substr(b, $i1, $i2)) FROM t1
+    }
+  }] [list $hexresult]
+  do_test substr-$id.2 [subst {
+    execsql {
+      SELECT hex(substr(x'$hex', $i1, $i2))
+    }
+  }] [list $hexresult]
+}
+
+# Basic SUBSTR functionality
+#
+substr-test 1.1 abcdefg 1 1 a
+substr-test 1.2 abcdefg 2 1 b
+substr-test 1.3 abcdefg 1 2 ab
+substr-test 1.4 abcdefg 1 100 abcdefg
+substr-test 1.5 abcdefg 0 1 a
+substr-test 1.6 abcdefg -1 1 g
+substr-test 1.7 abcdefg -1 10 g
+substr-test 1.8 abcdefg -5 3 cde
+substr-test 1.9 abcdefg -7 3 abc
+substr-test 1.10 abcdefg -100 98 abcde
+
+# Make sure everything works with long unicode characters
+#
+substr-test 2.1 \u1234\u2345\u3456 1 1 \u1234
+substr-test 2.2 \u1234\u2345\u3456 2 1 \u2345
+substr-test 2.3 \u1234\u2345\u3456 1 2 \u1234\u2345
+substr-test 2.4 \u1234\u2345\u3456 -1 1 \u3456
+substr-test 2.5 a\u1234b\u2345c\u3456c -5 3 b\u2345c
+
+# Basic functionality for BLOBs
+#
+subblob-test 3.1 61626364656667 1 1 61
+subblob-test 3.2 61626364656667 2 1 62
+subblob-test 3.3 61626364656667 1 2 6162
+subblob-test 3.4 61626364656667 1 100 61626364656667
+subblob-test 3.5 61626364656667 0 1 61
+subblob-test 3.6 61626364656667 -1 1 67
+subblob-test 3.7 61626364656667 -1 10 67
+subblob-test 3.8 61626364656667 -5 3 636465
+subblob-test 3.9 61626364656667 -7 3 616263
+subblob-test 3.10 61626364656667 -100 98 6162636465
+
+# If these blobs were strings, then they would contain multi-byte
+# characters.  But since they are blobs, the substr indices refer
+# to bytes.
+#
+subblob-test 4.1 61E188B462E28D8563E3919663 1 1 61
+subblob-test 4.2 61E188B462E28D8563E3919663 2 1 E1
+subblob-test 4.3 61E188B462E28D8563E3919663 1 2 61E1
+subblob-test 4.4 61E188B462E28D8563E3919663 -2 1 96
+subblob-test 4.5 61E188B462E28D8563E3919663 -5 4 63E39196
+subblob-test 4.6 61E188B462E28D8563E3919663 -100 98 61E188B462E28D8563E391 
+
+finish_test

www/lang.tcl

@@ -1,7 +1,7 @@
 #
 # Run this Tcl script to generate the lang-*.html files.
 #
-set rcsid {$Id: lang.tcl,v 1.128 2007/04/06 11:26:00 drh Exp $}
+set rcsid {$Id: lang.tcl,v 1.129 2007/05/15 01:13:47 drh Exp $}
 source common.tcl
 
 if {[llength $argv]>0} {
@@ -1455,8 +1455,9 @@ that is running.  Example:  "2.8.0"</td>
 with the <i>Y</i>-th character and which is <i>Z</i> characters long.
 The left-most character of <i>X</i> is number 1.  If <i>Y</i> is negative
 the the first character of the substring is found by counting from the
-right rather than the left.  If SQLite is configured to support UTF-8,
-then characters indices refer to actual UTF-8 characters, not bytes.</td>
+right rather than the left.  If <i>X</i> is string
+then characters indices refer to actual UTF-8 characters.  If
+<i>X</i> is a BLOB then the indices refer to bytes.</td>
 </tr>
 
 <tr>