2e47badb88
We now keep track of 3 sets during traversal: - keep: commits we've reached from head commits - drop: commits we've reached from tail commits - skip: ancestors of commits in both 'keep' and 'drop' Commits in 'keep' and/or 'drop' may be added later to the 'skip' set if we discover later that they are part of a common subgraph of the head and tail commits. From these sets we can calculate the commits we are interested in: lca commits are those in 'keep' and 'drop', but not in 'skip'. findtwixt commits are those in 'keep', but not in 'drop' or 'skip'. The "LCA" commit returned is a common ancestor such that there are no other common ancestors that can reach that commit. Although there can be multiple commits that meet this criteria, where one is technically lower on the commit-graph than the other, these cases only happen in complex merge arrangements and any choice is likely a decent merge base. Repainting is now done in paint() directly. When we find a boundary commit, we switch our paint color to 'skip'. 'skip' painting does not stop when it hits another color; we continue until we are left with only 'skip' commits on the queue. This fixes several mishandled cases in the current algorithm: 1. If we hit the common subgraph from tail commits first (if the tail commit was newer than the head commit), we ended up traversing the entire commit graph. This is because we couldn't distinguish between 'drop' commits that were part of the common subgraph, and those that were still looking for it. 2. If we traversed through an initial part of the common subgraph from head commits before reaching it from tail commits, these commits were returned from findtwixt even though they were also reachable from tail commits. 3. In the same case as 2, we might end up choosing an incorrect commit as the LCA, which is an ancestor of the real LCA. |
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| 386 | ||
| 68000 | ||
| 68020 | ||
| acme | ||
| adm/timezone | ||
| amd64 | ||
| arm | ||
| arm64 | ||
| lib | ||
| mips | ||
| power | ||
| power64 | ||
| rc | ||
| sparc | ||
| sparc64 | ||
| spim | ||
| sys | ||