PclZip throwing errors on PHP 8 - previously merged patch is incomplete

[DavidAnderson]

The patch merged in #52018 is incomplete, and when using PclZip::add(), you can still get fatal errors.

In UpdraftPlus (where we've had a number of affected users), the trace (from the relevant point onwards) is:

UpdraftPlus_Backup->makezip_addfiles, UpdraftPlus_PclZip->close, PclZip->add, PclZip->privAdd, PclZip->privAddFileList, PclZip->privAddFile

A patch is being attached.

[DavidAnderson]

Fix potentially invalid fread() call

[SergeyBiryukov]

Thanks for the patch!

I believe we should check $p_header['size'] instead of $p_entry['compressed_size'] though, as $p_entry is not set in this method, and the value passed to fread() is $p_header['size'].

[DavidAnderson]

@SergeyBiryukov Yes, sorry, that was just a copy/paste error - copied from the wrong place instead of my actual working change! New version coming up...

[DavidAnderson]

Correct patch

[SergeyBiryukov]

In 51686:

Filesystem API: Make sure to only call fread() on non-empty files in PclZip::privAddFile().

This avoids a fatal error on PHP 8 caused by passing a zero value to fread() as the $length argument, which must be greater than zero.

This commit also amends the previous solution for similar issues elsewhere in the file to ensure consistent type for string values, instead of changing the type from string to bool when trying to read from an empty file.

Follow-up to [50355].

Props DavidAnderson, jrf, SergeyBiryukov.
Fixes #54036.

[SergeyBiryukov]

Reopening for 5.8.1 consideration.

[desrosj]

In 51694:

Filesystem API: Make sure to only call fread() on non-empty files in PclZip::privAddFile().

This avoids a fatal error on PHP 8 caused by passing a zero value to fread() as the $length argument, which must be greater than zero.

This commit also amends the previous solution for similar issues elsewhere in the file to ensure consistent type for string values, instead of changing the type from string to bool when trying to read from an empty file.

Follow-up to [50355].

Props DavidAnderson, jrf, SergeyBiryukov.
Merges [51686] to the 5.8 branch.
Fixes #54036.