fix Issue2303, invalid characters in datetime field

[ArqamFarooqui110719]

Fix invalid character in datetime field, issue #2303

[ArqamFarooqui110719]

@ArqamFarooqui110719 maybe you could do a PR including a .test covering the cases:

 | expires                  |
 |--------------------------|
 | 2016-04-05T14:10:0x.00Z  |
 | 2016-04-05T14:10:00,00Z  |
 | 2016-04-05T14:10:00.h00Z |
 | 2016-04-05T14:10:00.0h0Z |
 | 2016-04-05T14:10:00.,00L |

I have tested above cases, and found that case-1 i.e. "2016-04-05T14:10:0x.00Z" was passing successfully (i.e. a WRONG behavior) because sscanf() function in src/lib/common/globals.cpp +626 file were not able to detect the invalid character.

I have fixed the code for that case, also include a .test file covering all cases that you mentioned in issue #2303.

[fgalan]

parse8601Time() has a strong C flavour, so I'd suggest not using C++ functions is possible. It seems a simpliar isalpha() function is available in ctype.h module. See example:

#include <stdio.h>
#include <ctype.h>

int main() {
    char ch = 'A';

    if (isalpha(ch)) {
        printf("%c is an alphabetic character.\n", ch);
    } else {
        printf("%c is not an alphabetic character.\n", ch);
    }

    return 0;
}