[sqlite] sqlite3_get_table and probable memory leak

Hi,

I have a simple function (used to get only one value from a database), 
as shown below, and I've struggled with it for a long time, without 
success. I use libsqlite3.6.13.
> int Database::execute(std::string query, std::string* result, 
> std::string* errMsg)
> {
>     int rc, tmpRowsCount, tmpColsCount;
>     char* zErrMsg;
>     char** tmpRes;
>     ostringstream tmp;
>
>     OS.logger->log(string("Executing query: ") + query, LOG);
>
>     rc = sqlite3_get_table(db, query.c_str(), &tmpRes, &tmpRowsCount, 
> &tmpColsCount, &zErrMsg);
>     if( rc!=SQLITE_OK )
>     {
>         tmp << "SQL error: " << zErrMsg;
>         if (errMsg != NULL)
>         {
>             errMsg->assign(zErrMsg);
>             sqlite3_free(zErrMsg);
>         }
>         OS.logger->log(tmp.str(), ERR);
>         tmp.str("");
>         sqlite3_free_table(tmpRes);
>         return -1;
>     }
>
>     if ((tmpRowsCount != 1) || (tmpColsCount != 1)) // TODO: check row 
> count
>     {
>         tmp << "Invalid number of rows (" << tmpRowsCount << ") or 
> columns (" << tmpColsCount << ")";
>         OS.logger->log(tmp.str(), ERR);
>         tmp.str("");
>         sqlite3_free_table(tmpRes);
>         return -2; // TODO: define error
>     }
>
>     if (result != NULL)
>         result->assign(tmpRes[1]);
>
>     sqlite3_free_table(tmpRes);
>
>     return 0;
> }
The problem is that after calling above function i get from mtrace:
> Memory not freed:
> -----------------
>    Address     Size     Caller
> 0x0005f9d0      0xf  at 0x401e8ef8
> 0x00062828    0x490  at 0x4012c920
Not freed 0xf at 0x0005f9d0 is OK, because it's caused by 
result->assign(tmpRes[1]). What I'm confused with is the 0x490 of not 
freed memory.

Here is raw mtrace log:
> = Start
> @ /usr/lib/libstdc++.so.6:(_Znwj+0x6c)[0x401e8ef8] + 0x61310 0x56
> @ /usr/lib/libstdc++.so.6:(_Znwj+0x6c)[0x401e8ef8] + 0x61370 0x1e
> @ /usr/lib/libstdc++.so.6:(_Znwj+0x6c)[0x401e8ef8] + 0x61398 0x67
> @ /usr/lib/libstdc++.so.6:(_ZNSsD1Ev+0x1c)[0x401d14e0] - 0x61398
> @ /usr/lib/libstdc++.so.6:(_ZNSsD1Ev+0x1c)[0x401d14e0] - 0x61370
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x5fbe8 0x58
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x62828 0x658
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x61370 0xe0
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x62e88 0x408
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x61458 0x230
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x61458
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x62828
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x61458 0x160
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x62828 0x490
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x5fe00 0x20
> @ /usr/lib/libsqlite3.so.0:[0x4012c920] + 0x5f9b8 0x10
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x61458
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x62e88
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x61370
> @ /usr/lib/libsqlite3.so.0:[0x4012c8ec] < 0x5fbe8
> @ /usr/lib/libsqlite3.so.0:[0x4012c8ec] > 0x5fbe8 0x18
> @ /usr/lib/libstdc++.so.6:(_Znwj+0x6c)[0x401e8ef8] + 0x5f9d0 0xf
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x5fe00
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x5f9b8
> @ /usr/lib/libsqlite3.so.0:(sqlite3_free+0x74)[0x400f3ec4] - 0x5fbe8
> @ /usr/lib/libstdc++.so.6:(_ZNSsD1Ev+0x1c)[0x401d14e0] - 0x61310
> = End
sqlite3_free_table is called for sure, because if I comment it, I get:
> Memory not freed:
> -----------------
>    Address     Size     Caller
> 0x0005f9b8     0x10  at 0x4012c920
> 0x0005f9d0      0xf  at 0x401e8ef8
> 0x000601a8     0x18  at 0x4012c8ec
> 0x00060208     0x20  at 0x4012c920
> 0x00062828    0x490  at 0x4012c920
Thanks in advance for any hints.

Cheers,
Maciej Miszczak
_______________________________________________
sqlite-users mailing list
sqlite-users@xxxxxxxxxx
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users