Fix#4600. String incrementation through the `++` operator is deprecated in Php 8.5. Because we make use of that operator to iterate through columns, we are particularly hard hit by that change - unaddressed, it causes over 2,000 errors in our test suite! It is, fortunately, not as difficult as I feared to correct. Replacing the `++` operator with a call to new method `StringHelper::stringIncrement` in 79 statements scattered over 31 source modules (in src, samples, test, and infra) eliminates all the messages in the test suite. It is possible that others are lurking, but I don't know a systematic way of determining if there are others. We'll stick with this for now, and deal with any others as they show up.
This PR will be applied to the master, release390, and release222 branches. It will not be applied to the release210 or release1291 branches, which will now accept security changes only.
Fix#1275, which had been closed as stale, and is now reopened pending the implementation of this PR. If there is a page break inside a defined print area, Excel may not render the print correctly unless the xml `brk` tag contains a `max` attribute. Libre Office renders it correctly. This seems like a bug in Excel (https://learn.microsoft.com/en-us/openspecs/office_standards/ms-oe376/b32ae11b-dee7-4dcb-9b46-a0feb32ce94f states that Office ignores min and max). PR #3345 (issue #3143) already addressed this problem by allowing the user to explicitly specify a `max` property in the PageBreak object. This PR eliminates the need for the user to make use of that kludge, by adding `max` to the xml whenever a page break is specified on a sheet with a defined print area. Xlsx Reader will now ignore the `max` attribute for row breaks, since it is no longer needed; it already ignores it for column breaks. The user may still set the `max` property if desired, just in case the new treatment is not adequate (I have not found a case where that is true). Two existing unit tests are very marginally changed because of this PR.
While we might never be able to have 100% of our code strict, we can at
the very least do it for all of our tests. This ensures that our tests
are using our API with the types as intended by the test author, and not
silently be cast to what our API requires.
* Permit Max Column for Row Breaks
Fix#3143. Page break was dropped. Difference between good and bad was the use of attribute `max` in `brk` tag in the good spreadsheet. However, `max` was *not* required in a similar spreadsheet. So the reason for the problem isn't completely explained. Nevertheless, it can't really hurt to capture the `max` value on read (if present) and generate it on write. This resolves the issue. User is also permitted to specify max column when setting a row break programatically. I am not yet in position to document when that might be a good idea.
* Case-sensitive Directory Name
Not a problem on my Windows system.
* Update Documentation and Add Tests
Change is necessitated by probable Excel bug.
* Unhappy With Initial Implementation
I kind of shoe-horned it in. Better to create a new PageBreak class, which will make it easier to accomodate any future surprises about page break handling. The only difficulty with the new approach is making sure getBreaks maintains backwards compatibility. New tests will ensure that.