elektraMerge fails if the root is top of a namespace

[atmaxinger]

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Steps to Reproduce the Problem

KeySet* ksBase = ksNew (0, KS_END);
KeySet* ksOurs = ksNew(0, KS_END);
KeySet* ksTheirs = ksNew (0, KS_END);

Key* baseRoot = keyNew ("system:/", KEY_END);
Key* oursRoot = keyNew ("system:/", KEY_END);
Key* theirsRoot = keyNew ("system:/", KEY_END);
Key* root = keyNew ("system:/", KEY_END);

ksAppendKey (ksBase, keyNew ("system:/test/k1", "k1", KEY_END));

ksAppendKey (ksOurs, keyNew ("system:/test/k1", "k1", KEY_END));
ksAppendKey (ksOurs, keyNew ("system:/test/k2", "k2", KEY_END));

ksAppendKey (ksTheirs, keyNew ("system:/test/k1", "k1", KEY_END));
ksAppendKey (ksTheirs, keyNew ("system:/test/k3", "k3", KEY_END));

Key* information = keyNew ("system:/", KEY_END);

KeySet* result = elektraMerge (ksOurs, oursRoot, ksTheirs, theirsRoot, ksBase, baseRoot, root, 1, information);

Expected Result

result contains the keys system:/test/k1, system:/test/k2 and system:/test/k3.

Actual Result

result is NULL

Why?

Internally, the algorithm will try to rename the keys in the keyset by removing the root name from the key name. For example, system:/test/k1 will be renamed to test/k1. However, this is not a valid key name as it does not start with a slash. This makes the rename operation fail.

[kodebach]

Seems like the merge algorithm doesn't correctly handle the fact, that root names end with a slash. Not sure how exactly the renaming is done, but it seems a good candidate for this function

https://github.com/ElektraInitiative/libelektra/blob/7f3f343cabcec561c87de8b41fbeae552699d697/src/libs/elektra/keyset.c#L1097

(I think it's currently only declared in kdbprivate.h)

[atmaxinger]

It uses keySetName.

https://github.com/ElektraInitiative/libelektra/blob/7f3f343cabcec561c87de8b41fbeae552699d697/src/libs/merge/kdbmerge.c#L313

[kodebach]

There is also this function

https://github.com/ElektraInitiative/libelektra/blob/7f3f343cabcec561c87de8b41fbeae552699d697/src/libs/elektra/keyname.c#L679

which may be a better fit.

In any case, I think the keySetName with the custom strremove should be replaced. AFAICT it doesn't handle escape sequences like \/ at all and may cause more problems than just this issue.

[flo91]

@markus2330 This looks also like an issue suited for the FLOSS course.

[github-actions[bot]]

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[github-actions[bot]]

I closed this now because it has been inactive for more than one year. If I closed it by mistake, please do not hesitate to reopen it or create a new issue with the remainder of this issue. Thank you for your contributions :sparkling_heart: