Infinite loop when parsing a simple header file

[nuclear868]

Describe the bug

When generating documentation, doxygen gets stuck on a specific file and the cpu usage goes to 100% (one core)
The console log stops at the line

Generating docs for file include/Base35.h...

It also happens when I run doxygen on this file alone, included in the example archive

Expected behavior

The generation should succeed

Screenshots

To Reproduce

There is an attached archive with a directory, containing 2 files: include/Base35.h and Doxyfile
I enter the directory, call doxygen Doxyfile and it gets stuck on the Base35.h file

Version

Operating system: Kubuntu 23.04

Doxygen 1.9.4 (comes with (K)ubuntu 23.04)
Also happens on Doxygen 1.9.8 (built from source)
Does not happen on Doxygen 1.9.1 (comes with (K)ubuntu 22.04)

Stack trace

As I saw, frame #4 (MemberList::writeDocumentation) does not exit.
This is backtrace from doxygen-1.9.4, as I am using gdb, which can automatically download debug symbols.

0x00005555558e81cc in isId (c=66) at /usr/src/doxygen-1.9.4-4/src/util.h:173
Downloading source file /usr/src/doxygen-1.9.4-4/src/util.h
173       return c=='_' || c>=128 || c<0 || isalnum(c) || c=='$';
(gdb) bt
#0  0x00005555558e81cc in isId (c=66) at /usr/src/doxygen-1.9.4-4/src/util.h:173
#1  addTemplateNames (s=..., n=..., t=...) at /usr/src/doxygen-1.9.4-4/src/memberdef.cpp:807
#2  0x00005555558f8ae3 in writeDefArgumentList (ol=..., scope=scope@entry=0x555556840ce8, md=md@entry=0x55555685f068) at /usr/src/doxygen-1.9.4-4/src/memberdef.cpp:948
#3  0x00005555559094ac in MemberDefImpl::writeDocumentation (this=0x55555685f060, ml=<optimized out>, memCount=<optimized out>, memTotal=<optimized out>, ol=..., scName=..., container=0x555556843f28, inGroup=false,
showEnumValues=false, showInline=false) at /usr/src/doxygen-1.9.4-4/src/memberdef.cpp:3519
#4  0x0000555555917ec7 in MemberList::writeDocumentation (this=this@entry=0x555556847f30, ol=..., scopeName=..., container=container@entry=0x555556843f28, title=..., showEnumValues=showEnumValues@entry=false,
showInline=false) at /usr/src/doxygen-1.9.4-4/src/memberlist.cpp:711
#5  0x0000555555736502 in FileDefImpl::writeMemberDocumentation (this=this@entry=0x555556843f20, ol=..., lt=<optimized out>, title=...) at /usr/src/doxygen-1.9.4-4/src/filedef.cpp:1669
#6  0x000055555573eb62 in FileDefImpl::writeDocumentation (this=0x555556843f20, ol=...) at /usr/src/doxygen-1.9.4-4/src/filedef.cpp:949
#7  0x000055555570b4b6 in generateFileDocs () at /usr/src/doxygen-1.9.4-4/src/doxygen.cpp:8208
#8  0x000055555570e663 in generateOutput () at /usr/src/doxygen-1.9.4-4/src/doxygen.cpp:12499
#9  0x000055555568a072 in main (argc=2, argv=0x7fffffffdbe8) at /usr/src/doxygen-1.9.4-4/src/main.cpp:38
(gdb)

Additional context

doxygenIssue.tar.gz

This is an example containing the Doxyfile and the file from the project that reproduces the issue. I think that the files that it includes (Buffer.h and EncodeError.h) are not needed.

[albert-github]

Nice small example and references to the different versions.

When running with the current master (1.10.0 (d062df6)) under Windows it looks like the process is stuck.

I looked in the code and saw the line:

inline namespace Rigel {

and when removing the inline we get:

namespace Rigel {

and doxygen runs, but this cannot be the real solution.

Bisecting gave that the problem is introduced between doxygen 1.9.1 and 1.9.2 and more precise:

592aaa4f17d73ec8c475df0f44efaea8cc4d575c is the first bad commit
Commit: 592aaa4f17d73ec8c475df0f44efaea8cc4d575c [592aaa4]
Parents: 98c67549bc
Date: Sunday, April 11, 2021 9:22:59 PM
Commit Date: Thursday, April 22, 2021 7:34:13 PM
Refactoring: remove implicit conversion from QCString to const char *

This commit changes the following in relation to string use
- The implicit convert from 'QCString' to 'const char *' is removed
- Strings parameters use 'const QCString &' as much as possible in favor
  over 'const char *'
- 'if (s)' where s is a QCString has been replaced by 'if(!s.isEmpty())'
- data() now always returns a valid C-string and not a 0-pointer.
- when passing a string 's' to printf and related functions 'qPrint(s)' is
  used instead of 's.data()'
- for empty string arguments 'QCString()' is used instead of '0'
- The copy() operation has been removed
- Where possible 'qstrcmp(a,b)==0' has been replaces by 'a==b' and
  'qstrcmp(a,b)<0' has been replaced by 'a<b'
- Parameters of string type that were default initialized with '= 0' are
  no initialized with '= QCString()'

@doxygen any idea?

[doxygen]

@nuclear868 Please verify if the referenced commit fixes the problem for you. Do not close the issue. This will be done when the next official version is released.

[nuclear868]

Yes, the referenced commit fixes the issue and Doxygen is able to generate documentation for the entire project that I am using.

[doxygen]

This issue was previously marked 'fixed but not released',
which means it should be fixed in doxygen version 1.10.0.
Please verify if this is indeed the case. Reopen the
issue if you think it is not fixed and please include any additional information
that you think can be relevant (preferably in the form of a self-contained example).