Bug #60616 [Asn->Csd]: odbc_fetch_into returns junk data at end of multi-byte char fields

Edit report at https://bugs.php.net/bug.php?id=60616&edit=1 ID: 60616 Updated by: keyur@php.net Reported by: j dot faithw at yahoo dot com Summary: odbc_fetch_into returns junk data at end of multi-byte char fields -Status: Assigned +Status: Closed Type: Bug Package: ODBC related Operating System: Linux PHP Version: 5.3.8 Assigned To: keyur Block user comment: N Private report: N New Comment: The fix for this bug has been committed. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. For Windows: http://windows.php.net/snapshots/ Thank you for the report, and for helping us make PHP better. Thanks for the note! I fixed the problem for CHAR fields as well (https://github.com/php/php-src/commit/65364fe7d00319f6bfb4814980988d34183f9f78) Please try and reopen this if it doesn't work. Previous Comments: ------------------------------------------------------------------------ [2014-07-29 09:45:00] j dot faithw at yahoo dot com The patch adds support for WVARCHAR which should fix issues with that datatype but this bug was for the CHAR datatype which is still broken. ------------------------------------------------------------------------ [2014-07-28 23:30:25] keyur@php.net The fix for this bug has been committed. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. For Windows: http://windows.php.net/snapshots/ Thank you for the report, and for helping us make PHP better. ------------------------------------------------------------------------ [2014-07-28 23:29:06] keyur@php.net Thank you for your bug report. This issue has already been fixed in the latest released version of PHP, which you can download at http://www.php.net/downloads.php Patch committed to Git https://github.com/php/php-src/commit/00546bc9b7cb8208c27de9c6ebd12156401a5607 ------------------------------------------------------------------------ [2011-12-28 11:57:14] j dot faithw at yahoo dot com Description: ------------ This relates to bug#25792, which has been marked Analyzed but does not seem to be fixed. When retrieving data from a char() field containing multi-byte characters using e.g. odbc_fetch_into(), if the number of bytes used exceeds the number of characters then junk data is returned at the end of the string. I have experience this with Postgres char columns when the database is created with e.g the EUC_CN character encoding(createdb -E EUC_CN). This encoding uses between 1 and 3 bytes per character. So a char(10) could need up to 30 bytes. The problem is in the odbc_bindcols function in ext/odbc/php_odbc.c SQLColAttributes is called with SQL_COLUMN_DISPLAY_SIZE but this indicates the maximum number of characters required not the number of bytes. This means the buffer allocated for the value may not be big enough result->values[i].value=(char)emalloc(displaysize+1); Later on in e.g. odbc_fetch_into Z_STRLEN_P(tmp) = result->values[i].vallen; Z_STRVAL_P(tmp) = estrndup(result->values[i].value,Z_STRLEN_P(tmp)); This can result in a vallen bigger that displaysize. But the ODBC driver will only fill in at most displaysize+1 bytes(including null terminator). This means character data is missed and junk bytes are returned instead. The same problem may exist in ext/pdo_odbc/odbc_stmt.c. Where rc = SQLColAttribute(S->stmt, colno+1, SQL_DESC_DISPLAY_SIZE, NULL, 0, NULL, &displaysize); is called. But I have not tested this. The following fixes odbc_bindcols for the char(x) datatype. I believe 4 bytes is the maximum required for any character encoding. php_odbc.c:line 988 if (result->values[i].coltype == SQL_CHAR) { //If using a multibyte character encoding //number of bytes could be 4*SQL_COLUMN_DISPLAY_SIZE. //Without this workaround various functions //e.g. odbc_fetch_into will return data with a null after //diplaysize bytes and extra junk data at the end as //vallen can be bigger than displaysize. Tested using //PostgreSQL with EUC_CN encoding. displaysize*=4; } The fix may be needed for other data types as well as SQL_CHAR. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=60616&edit=1