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

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FossilOrigin-Name: 75d573080d03ee48fe88710f70c6875ff9cae19c
This commit is contained in:
drh
2007-05-15 01:13:47 +00:00
parent 2a9abf61c7
commit f764e6fc3d
5 changed files with 150 additions and 25 deletions
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48
src/func.c
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@@ -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 );
z = sqlite3_value_text(argv[0]);
if( z==0 ) return;
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 ){
@@ -177,16 +192,21 @@ static void substrFunc(
if( p1+p2>len ){
p2 = len-p1;
}
for(i=0; i<p1 && z[i]; i++){
if( (z[i]&0xc0)==0x80 ) p1++;
if( p0type!=SQLITE_BLOB ){
for(i=0; i<p1 && z[i]; i++){
if( (z[i]&0xc0)==0x80 ) p1++;
}
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p1++; }
for(; i<p1+p2 && z[i]; i++){
if( (z[i]&0xc0)==0x80 ) p2++;
}
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);
}
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p1++; }
for(; i<p1+p2 && z[i]; i++){
if( (z[i]&0xc0)==0x80 ) p2++;
}
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p2++; }
if( p2<0 ) p2 = 0;
sqlite3_result_text(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
}
/*