[6.36] Backport of #19318 #19752
Open
[6.36] Backport of #19318 #19752
+152
−0
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…llection element type A call to `TTree::Branch` with the branch type being an STL collection with an element type derived from an unsplittable base class (i.e. with a custom streamer) would fail with the following error message: ``` Fatal in <TBranchElement::InitializeOffsets>: Could not find the real data member 'objects' when constructing the branch 'objects' [Likely an internal error, please report to the developers]. aborting ``` Due to the fact that InitializeOffsets was not able to properly compute the offset of the base class of the element type. Unfortunately the error message itself was obscure, since the repetition of the word 'objects' in this case simply refers to the top-level branch name. What is really happening is that the function logic mixes the calculation of the offsets of base classes with the calculation of offsets of data members of a class in the same code path. For this reason, the failure should have hinted at this by specifying that the first 'objects' was actually 'base class of the type of the objects branch'. In the particular configuration of an STL collection type, the function needs to compute the offset of the base class of its element type. The function generally looks for TRealData of each data member and base class. But when the base class is unsplittable, this will not work anyway. The logic of the function is slightly extended so that if the name of the data member being currently looked at is actually of the type 'nameOfBranch.BaseClassName', i.e. we are not looking for a data member for the base class of the element type of an STL collection, we remove all the leading part of the name until the base class name itself. This helps because other parts of the function compare the current data member name with the base class name and if they are equal, the data member name is completely removed. When there is no data member name to look at, the function simply skips all the logic related to TRealData and directly computes the offset of the base class, which is the desired behaviour in this case. A test is added to exemplify the case at hand. Co-authored-by: Philippe Canal <[email protected]>
Test Results0 tests 0 ✅ 0s ⏱️ Results for commit a30a00f. ♻️ This comment has been updated with latest results. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.