Strip leading spaces in QHP file

[ferdymercury]

Describe the bug
qhelpgenerator crashes with some doxygen-generated qhp files on big projects with a lot of nested classes. This is because there are lines in the file that are too long (12.000 indentation spaces before the content in the line starts, and that is repeated on every line).

Expected behavior
It would be nice to have a Doxyfile flag to strip leading spaces after generating the index.qhp file, before running qhelpgenerator. Even if it makes the file less correct from the indentation point of view.

Screenshots

qhelpgenerator index.qhp
       Error in line 134919: Premature end of document.
# Let us strip spaces, see https://stackoverflow.com/questions/59715196/how-can-i-efficiently-remove-unnecessary-whitespace-from-xml-files-with-a-linux
sed -i -e '/^ */s///' -e '/ *$/s///' index.qhp
qhelpgenerator index.qhp
       ...
       Documentation successfully generated.

To Reproduce
Download index.qhp.gz and run qhelpgenerator on it.

Version
Doxygen 1.9.4 (9948297*)
Qt Help Generator version 1.0 (Qt 4.8.7)

Additional context
This documentation is generated within the ROOT project of CERN.

[albert-github]

The fix itself would not be to difficult and the size gain can be quite big (the original file has a size of 4,989,272,510 bytes and when running the sed the resulting file has a size of 54,170,110 bytes).
When running the qhelpgenerator on the original file we get an error whilst when running on the reduced file there is no error though when trying to view the file in the assistant (version 6.1.2) it doesn't show the result (might be that there are still some files missing as I only have the qhp file).
The readability of the resulting file after the sed is not the best either.

I'm a bit reluctant to remove the spaces.

@doxygen what is your opinion?

[albert-github]

Maybe a way would be to switch GENERATE_QHP from a boolean to a variable with 3 values:

• NO, no generation it is like it is now
• YES, generation like it is done now.
• CONDENSED, like YES but removing the leading spaces.

@doxygen what do you think?

[doxygen]

@albert-github I would make a debug option (-d qhp) to enable the non-condensed output. Rationale: the file is meant for processing by tools, not for humans to read. I also don't think the current indenting is correct, there seems to be some missing cases where the indent should decrease. The following example shows members of TApplication yet the indentation increases 4 times (looks like this is related to enums).

                      <section title="fIsChecked" ref="classROOT_1_1Experimental_1_1Internal_1_1RResultBase.html#a27e82995641a3af8aa5ad7120f2bbc41" />
                      <section title="TApplication" ref="classTApplication.html">
                        <section title="EExitOnException" ref="classTApplication.html#a2f699906b45ca8bd6404e2d0cc54658b">
                          <section title="kDontExit" ref="classTApplication.html#a2f699906b45ca8bd6404e2d0cc54658ba79976c51b779212ca7227340001f7dfe" />
                          <section title="kExit" ref="classTApplication.html#a2f699906b45ca8bd6404e2d0cc54658baa261b49ff157536d21bc5164db0ca7fc" />
                          <section title="kAbort" ref="classTApplication.html#a2f699906b45ca8bd6404e2d0cc54658ba7e71cb99bd0e852d0539418b80bedf4e" />
                          <section title="EFileBits" ref="classTApplication.html#a9cdab6aad3ca84066f168c04aae56bfc">
                            <section title="kExpression" ref="classTApplication.html#a9cdab6aad3ca84066f168c04aae56bfca101cd6dd0fcf41dc84dddef2c21cce78" />
                            <section title="EStatusBits" ref="classTApplication.html#a4153a52a08881b29a3b500e63b57cff4">
                              <section title="kProcessRemotely" ref="classTApplication.html#a4153a52a08881b29a3b500e63b57cff4a44c307e438d431b39e078b8171e2245d" />
                              <section title="kDefaultApplication" ref="classTApplication.html#a4153a52a08881b29a3b500e63b57cff4ac9b451860b304bb4b204cc6391e2ff03" />
                              <section title="TApplication" ref="classTApplication.html#a2f0237bc6d078165175a97d0072fe178" />

[albert-github]

• OK. I think it is a good idea to use the -d qhp for this.
• I'll also have a look whether or not the enum is the cause of "strange" indentations

[albert-github]

I've just pushed a proposed patch, pull request #9068 (implementing the compressed form).

[albert-github]

I've just pushed a proposed patch, pull request #9069 (regarding the wrong indentation in case of enums)

[albert-github]

Code, of both pull requests, has been integrated in master on GitHub (please don't close the issue as this will be done at the moment of an official release).

[ferdymercury]

Thanks for the fix. We have now compiled doxygen with git master.

Doxygen version used: 1.9.4 (bba8351)

However, we get now a different type of error:

Error in line 1: Opening and ending tag mismatch.
error: failed to run qhelpgenerator on index.qhp

Find attached the newly obtained qhp file.
index.qhp.gz