Crash when using @startgit

Question

Based on the question https://forum.plantuml.net/13557/support-for-the-different-%40start-commands?show=13557I did a bit a larger test.

I used on the plantuml repository the command:

git log --all --graph --decorate=short --abbrev-commit --oneline

redirected it tho a file and placed the command @startgit at the beginning of the file and @endgit at the end.

I ran plantuml on it with version: PlantUML version 1.2021.9beta3 (Unknown compile time)

and got a crash:

this=(7,34)
java.lang.UnsupportedOperationException: (7,34)
        at net.sourceforge.plantuml.gitlog.CursorPosition.getDownFromInternal(CursorPosition.java:211)
        at net.sourceforge.plantuml.gitlog.CursorPosition.getDownFromHere(CursorPosition.java:114)
        at net.sourceforge.plantuml.gitlog.Commit.getAncestors(Commit.java:112)
        at net.sourceforge.plantuml.gitlog.GNodeBuilder.<init>(GNodeBuilder.java:61)
        at net.sourceforge.plantuml.gitlog.GitDiagram.<init>(GitDiagram.java:62)
        at net.sourceforge.plantuml.gitlog.GitDiagramFactory.createSystem(GitDiagramFactory.java:66)
        at net.sourceforge.plantuml.PSystemBuilder.createPSystem(PSystemBuilder.java:133)
        at net.sourceforge.plantuml.BlockUml.getDiagram(BlockUml.java:163)
        at net.sourceforge.plantuml.SourceFileReaderAbstract.getGeneratedImages(SourceFileReaderAbstract.java:151)
        at net.sourceforge.plantuml.Run.manageFileInternal(Run.java:520)
        at net.sourceforge.plantuml.Run.processArgs(Run.java:403)
        at net.sourceforge.plantuml.Run.manageAllFiles(Run.java:370)
        at net.sourceforge.plantuml.Run.main(Run.java:198)

The total file might be a bit large, but I don't think that is the problem her (just a guess).

The big question is why does it go wrong?

Comments

Looks like I've been able to reduce the problem slightly (this is from the doxygen repository:

@startgit
* c77aea4c Added initial script for Travis CI service
*   38059b8b Merge pull request #7 from ogbash/experimental/prototype
|\
| * be4c107a Add scopes to Fortran prototype name parsing.
| * f138b8f3 Prototype scan for function, does not yet catch parameter types.
* |   9bfa0dd1 Merge pull request #6 from bo0ts/tabify
|\ \
| * | 4ed8db1d configgen.py: Tabify
* | |   8e79dfb3 Merge pull request #2 from pepr/master
|\ \ \
| * | | 574f39d4 French maintainer added, TranslatorFrench converted to UTF-8.
| * | | b25d914d .gitignore removed
| * | | 4a5d43a4 Merge branch 'master' of https://github.com/doxygen/doxygen.git
| |\| |
| * | | 46dba7a8 Muhammad Bashir Al-Noimi is the new maintainer for the Arabic language
| * | | f7db425d Minor fix of the doc/language.tpl; .gitignore with __*/
| | |/
| |/|
* | | 59f32335 Replaced empty configure.bin with real one
| |/
|/|
* | eb193634 Bug 700709 - typedef warning when "using" some operator functions
* | 580c6607 Fixed build issue when using --with-sqlite3 option
|/
* 3e8a7fbd Documentation fixes provided by Albert
* 7abdf4e5 Fixed rwx attributes of tmake files
* 852cf316 Removed obsolete file
@endgit

Stack trace identical, just the

this=(4,14)
java.lang.UnsupportedOperationException: (4,14)

is different.

---

A bit further looks like the construct:

| * | | 4a5d43a4 Merge branch 'master' of https://github.com/doxygen/doxygen.git
| |\| |
| * | | 46dba7a8 Muhammad Bashir Al-Noimi is the new maintainer for the Arabic language

is the problem. i.e. the merge / split between 2 branches. (replacing the "\" by a space and the tree. now not representing the correct situation, generates. When replacing the "\" with "/" there is also a crash).