Ubuntu 14.04.1 libmyodbc 5.1.10-3 bug

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== Comment: #0 - Xiao Yuan Li <email address hidden> - 2014-11-20 21:58:30 ==
---Problem Description---
Ubuntu 14.04.1 libmyodbc 5.1.10-3 reset the row-count loop variable of user application to zero and it results in user application core dump

---uname output---
Linux (none) 3.13.0-39-generic #66-Ubuntu SMP Tue Oct 28 13:30:27 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Machine Type = x64

---Debugger---
A debugger is not configured

---Steps to Reproduce---
 user application query multi-rows data from mysql, libmyodbc function "copy_ansi_result ()" will reset row-count loop variable "j" to 0.
Then it will result in the return value of "SQLGetData()" is "SQL_NO_DATA".
user application will core dump.

int fetch_all_data(SQLHSTMT V_OD_hstmt, DB_RES *res) {
        SQLRETURN V_OD_erg; // result of functions
        DB_ROW row = NULL;
        SQLUSMALLINT i;
        char *temp;
#if USE_SQLLEN
        SQLLEN indicator;
#else
        SQLINTEGER indicator;
#endif
        long j;

        //GRID_LOG_DEBUG(("DEBUG: in fetch\n"));
        res->fetched_rows=malloc((res->row_count+1)*sizeof(char*));
        if (!res->fetched_rows) {
                        GRID_LOG(("ERROR: malloc memory error for fetch."));
                        return -1;
        }
        memset(res->fetched_rows, 0, (res->row_count+1)*sizeof(char*));
        for(j=0;j<res->row_count;j++){//fetch each row
                V_OD_erg = SQLFetchScroll(V_OD_hstmt,SQL_FETCH_NEXT,0);
                if(!SQL_SUCCEEDED(V_OD_erg)){
                        free(res->fetched_rows);
                        return -1;
                        }
                row=malloc(res->field_count*sizeof(char*));
                if (!row) {
                                free(res->fetched_rows);
                                GRID_LOG(("ERROR: malloc memory error for fetch(first)."));
                                return -1;
                }
                memset(row, 0, res->field_count*sizeof(char*));
                for (i = 1; i <= res->field_count; i++) {//get each column for each row
                    V_OD_erg = SQLGetData(V_OD_hstmt, i, SQL_C_CHAR, NULL, 0, (SQLLEN *) (&indicator));//get the column length
                        if (SQL_SUCCEEDED(V_OD_erg)) {
                                /* Handle null columns */
                                if (indicator == SQL_NULL_DATA){
temp=malloc(1);//for some propramm use dbodbc_row[0] directly, not check if the result of dbodbc_fetch_row is NULL or not
                                        if (!temp) {
                                                free(res->fetched_rows);
                                                GRID_LOG(("ERROR: malloc memory error for fetch(third)."));
                                                return -1;
                                }
                                        memset(temp, 0, 1);
                                        row[i-1]=temp;
                                        //GRID_LOG_DEBUG(("DEBUG: Column %u :NULL\n", i));
                                }else{
                                        temp=malloc(indicator+1);
                                        if (!temp) {
                                                free(res->fetched_rows);
                                                GRID_LOG(("ERROR: malloc memory error for fetch(third)."));
                                                return -1;
                            }
                                        memset(temp, 0, indicator+1);
                                        V_OD_erg = SQLGetData(V_OD_hstmt, i, SQL_C_CHAR, temp, indicator+1, (SQLLEN *) (&indicator));//get the column data
                                        row[i-1]=temp;
                        //GRID_LOG_DEBUG(("DEBUG: Column %u [%d]: %s\n", i,indicator, temp));
                                }
                        }else{ temp=malloc(1);//for some propramm use dbodbc_row[0] directly, not check if the result of dbodbc_fetch_row is NULL or not
                                if (!temp) {
                                        free(res->fetched_rows);
                                        GRID_LOG(("ERROR: malloc memory error for fetch(third)."));
                                        return -1;
                        }
                                memset(temp, 0, 1);
                                row[i-1]=temp;
                                GRID_LOG(("ERROR: get the column length failed!\n"));
                        }
                }//end for i
                //GRID_LOG_DEBUG(("DEBUG: Fetched [%d] Column\n", res->field_count));
                res->fetched_rows[j]=row;
        }//end for j
        res->current_row_num=0;
        return 0;
}
----following is gdb debug info---
please refer the following gdb info and i is res->field_count/j is res->row_count

mysql> select id from lic_pollers order by id (this is the following query sql)
    -> ;
+----+
| id |
+----+
| 1 |
| 2 |
+----+
2 rows in set (0.03 sec)

11/10/2014 12:16:09 AM - LIC field_count=1, row_count=2
484 fetch_ret=fetch_all_data(V_OD_hstmt,res);
(gdb) s
fetch_all_data (V_OD_hstmt=0x647280, res=0x647dc0) at database.c:669
669 DB_ROW row = NULL;
(gdb) n
679 GRID_LOG_DEBUG(("DEBUG: in fetch\n"));
(gdb)
11/10/2014 12:16:15 AM - LIC DEBUG: in fetch
680 res->fetched_rows=malloc((res->row_count+1)*sizeof(char*));
(gdb) watch i
Hardware watchpoint 2: i
(gdb) watch j
Hardware watchpoint 3: j
(gdb) n
681 if (!res->fetched_rows) {
(gdb) n
685 memset(res->fetched_rows, 0, (res->row_count+1)*sizeof(char*));
(gdb)
686 for(j=0;j<res->row_count;j++){//fetch each row
(gdb)
Hardware watchpoint 3: j

Old value = 140737488345312
New value = 0
0x000000000040728c in fetch_all_data (V_OD_hstmt=0x647280, res=0x647dc0) at database.c:686
686 for(j=0;j<res->row_count;j++){//fetch each row
(gdb)
687 V_OD_erg = SQLFetchScroll(V_OD_hstmt,SQL_FETCH_NEXT,0);
(gdb)
688 if(!SQL_SUCCEEDED(V_OD_erg)){
(gdb)
692 row=malloc(res->field_count*sizeof(char*));
(gdb)
693 if (!row) {
(gdb)
698 memset(row, 0, res->field_count*sizeof(char*));
(gdb)
699 for (i = 1; i <= res->field_count; i++) {//get each column for each row
(gdb)
Hardware watchpoint 2: i

Old value = 0
New value = 1
0x0000000000407342 in fetch_all_data (V_OD_hstmt=0x647280, res=0x647dc0) at database.c:699
699 for (i = 1; i <= res->field_count; i++) {//get each column for each row
(gdb)
700 V_OD_erg = SQLGetData(V_OD_hstmt, i, SQL_C_CHAR, NULL, 0, (SQLLEN *) (&indicator));//get the column length
(gdb)
701 if (SQL_SUCCEEDED(V_OD_erg)) {
(gdb)
703 if (indicator == SQL_NULL_DATA){
(gdb)
714 temp=malloc(indicator+1);
(gdb)
715 if (!temp) {
(gdb)
720 memset(temp, 0, indicator+1);
(gdb)
721 V_OD_erg = SQLGetData(V_OD_hstmt, i, SQL_C_CHAR, temp, indicator+1, (SQLLEN *) (&indicator));//get the column data
(gdb)
722 row[i-1]=temp;
(gdb)
723 GRID_LOG_DEBUG(("DEBUG: Column %u [%d]: %s\n", i,indicator, temp));
(gdb)
11/10/2014 12:17:05 AM - LIC DEBUG: Column 1 [1]: 1
699 for (i = 1; i <= res->field_count; i++) {//get each column for each row
(gdb)
Hardware watchpoint 2: i

Old value = 1
New value = 2
0x0000000000407591 in fetch_all_data (V_OD_hstmt=0x647280, res=0x647dc0) at database.c:699
699 for (i = 1; i <= res->field_count; i++) {//get each column for each row
(gdb) n
737 GRID_LOG_DEBUG(("DEBUG: Fetched [%d] Column\n", res->field_count));
(gdb)
11/10/2014 12:17:18 AM - LIC DEBUG: Fetched [1] Column
738 res->fetched_rows[j]=row;
(gdb)
686 for(j=0;j<res->row_count;j++){//fetch each row
(gdb) n
Hardware watchpoint 3: j

Old value = 0
New value = 1
0x00000000004075eb in fetch_all_data (V_OD_hstmt=0x647280, res=0x647dc0) at database.c:686
686 for(j=0;j<res->row_count;j++){//fetch each row
(gdb)
687 V_OD_erg = SQLFetchScroll(V_OD_hstmt,SQL_FETCH_NEXT,0);
(gdb)
688 if(!SQL_SUCCEEDED(V_OD_erg)){
(gdb) n
692 row=malloc(res->field_count*sizeof(char*));
(gdb) n
693 if (!row) {
(gdb) n
698 memset(row, 0, res->field_count*sizeof(char*));
(gdb)
699 for (i = 1; i <= res->field_count; i++) {//get each column for each row
(gdb)
Hardware watchpoint 2: i

Old value = 2
New value = 1
0x0000000000407342 in fetch_all_data (V_OD_hstmt=0x647280, res=0x647dc0) at database.c:699
699 for (i = 1; i <= res->field_count; i++) {//get each column for each row
(gdb) n
700 V_OD_erg = SQLGetData(V_OD_hstmt, i, SQL_C_CHAR, NULL, 0, (SQLLEN *) (&indicator));//get the column length
(gdb)
Hardware watchpoint 3: j

Old value = 1
New value = 0
0x00007ffff6aa3685 in copy_ansi_result () from /usr/lib/x86_64-linux-gnu/odbc/libmyodbc.so

Userspace tool common name: libmyodbc

The userspace tool has the following bit modes: 64-bit

Userspace rpm: libmyodbc-5.1.10-3

Userspace tool obtained from project website: na

[Ubuntu Foundations Team Bug Bot (crichton)]

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------- Comment From <email address hidden> 2014-12-01 15:01 EDT-------
Any updates from Canonical on this?

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------- Comment on attachment From <email address hidden> 2014-12-12 07:59 EDT-------

add gdb bt full info

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------- Comment From <email address hidden> 2015-01-19 17:24 EDT-------
There is no change in this bug for more than 1 month. What are the next steps here?