9.9 (LTS)/1.14.0 - Use of Reference Branch for New Code with SCM Disabled

[nikleo-eng]

Describe the bug
With SCM disabled, when I set for the new code of branches, eg child_branch, the reference to a master stable branch, eg parent_branch, the first analysis of child_branch shows correctly the new/modified files as new code with respect to parent_branch, but the second and successive analyses of child_branch not compare completely the all files of child_branch with the all files of parent_branch; in the second and successive analyses are showed as new code, not the new/modified files from the first anaylsis + the new/modified files (ever with respect to parent_branch) of these analyses, but only the new/modified files of these last analyses with respect to the respectively previous analysis.

So, if the quality gate of the first analysis is failed, the second analysis - that treats only the differences between the first and the second analysis - has a succeded quality gate (obviously if in the differences not are introduced issues that bring the new quality gate in failure); same behaviour between the second and the third analysis, and so on ... I think this behaviour is a bug.

To Reproduce
Steps to reproduce the behavior:

1. Create a project with new code setted on reference branch
2. Analyze the reference branch
3. Create a branch with some code added, with respect to the reference branch
4. Analyze the branch, the showed infos on the added code are correct
5. Add extra different new code to the branch (with respect to the reference branch and the code of 3.)
6. Analyze the branch again, the showed infos are relative only to the new code of 5. (and not to the new code of 3. + 5.)

Expected behavior
With the use of reference branch for new code, I'm expecting that every analysis of child_branch compares all files from child_branch with all files of parent_branch: I expect that the analyses are ever complete and not incremental with respect to previous analysis; in this way, the quality gate of every analysis shows the complete situation of complete source code.

Software Versions

• SonarQube Version: 9.9 (LTS)
• Plugin Version: 1.14.0