[RESOLVED] strange bug: fetching mysql rows suddenly stops script

dylanreid

Hello All :],

I've spent quite some time trying to figure out this particularly strange bug and haven't gotten anywhere so perhaps a fresh pair of eyes on the forums can help me out!

here is the code snippet that causes problems:

						<optgroup label="Force Transition">
<?

			$query = "SELECT transactionStatus_id, description, defaultTransitionDescription FROM transactionStatus ORDER BY transactionStatus.transactionStatus_id";
			$result = $GLOBALS['sql']->query($query) or die("Query failed : " . $GLOBALS['sql']->error);
			while (1) {
				$line = $result->fetch_array( MYSQLI_ASSOC);
				if( $line) {
										echo "<option value=F".$line['transactionStatus_id'].">".htmlspecialchars( '['.$line['description'].'] '.$line['defaultTransitionDescription'])."</option>\n";

				} else {
					echo "stopping!";
					break;
				}

			}


?>
						</optgroup>
<?
				$result->free();

?>

at the moment it's a bit hacked up as i attempted to find where it's breaking.. the actual line that it just stops on is the line

"$line = $result->fetch_array( MYSQLI_ASSOC);"

the database query is sound, it returns around 20 rows that should be put into a select statement. however, when looking at the source for the page that's generated it prints out about 12 options and then just ends the script, it does not print out "stopping!", or "</optgroup>" or anything else for that matter.

it's really quite a confusing bug and my colleagues and i are really stumped. any help would be most appreciated!

thanks in advance,
dylan

Piranha

Don't use short tags. Use <?php instead.
It should return around 20 rows. And it prints out about 12 options. Please check that the numbers are exact instead of an estimated count. If the count is a little wrong in both counts it could easily be that it is in fact finished.
Do you get any error message? If so please post it here. Start the file with error_reporting(E_ALL) to get most messages.

Your while-loop seems strange. Try this instead:

while ($line = $result->fetch_array( MYSQLI_ASSOC)) {

Use htmlspecialchars as is shown in the manual to handle single quotes as well:
```
htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES)
```

dylanreid

1. Don't use short tags. Use <?php instead.

fixed, unfortunately no difference.

2. It should return around 20 rows. And it prints out about 12 options. Please check that the numbers are exact instead of an estimated count. If the count is a little wrong in both counts it could easily be that it is in fact finished.

sorry for not being exact.. there are 19 rows that it should return. also, i was a bit off on the 12 being printed out.. at the moment it's actually 5 rows. and i say "at the moment" because it changes.. more at the end of this post

3. Do you get any error message? If so please post it here. Start the file with error_reporting(E_ALL) to get most messages.

no error messages are printed with that function called at the top of the code.

4. Your while-loop seems strange. Try this instead:
while ($line = $result->fetch_array( MYSQLI_ASSOC)) {

it is only in that format for debugging, it was in the format you have before i started dismantling it looking for any insights.

5. Use htmlspecialchars as is shown in the manual to handle single quotes as well:
htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES)

ok fixed that as well, still not working.

here is another bit of information that is equally boggling. when i put the line

echo "123456789";

right above the option echo, i get 4 rows returned. however, if this line is

echo "12345678";

then i get 5 rows returned (numbers 1-8 returns 4 rows, i haven't experimented very far past 9). so it's almost like thie bug is somehow related to output.

still very confused 😕 i hope what i've written is clear, and thank you again for taking the time to read :]

dylan

Piranha

Strange, I have no idea what it can be.

Is it always stopping at the same database row (the same database id)?

What happens if you only echo the id, does it work then?

If you look at the generated html (the code), can you see the rest?

dylanreid

we finally fixed this bug if anyone is interested.. it turned out that there was no correlation with this bug and the while loop.. that was just a product of the real problem.

there was a function that returned a variable and both of these had the same name ($promoDiscount and promoDiscount()).. the bug was that the function was returning the function itself instead of the variable, causing infinite recursion.. apache then shut down the script when it detected the infinite loop.

so infinite loops strike again! anyway, something to keep in mind next time a script mysteriously ends for no apparent reason.. this was quite a malicious bug, thanks for anyone who read the post!

dylan