When a pull request is merged, regardless of strategy, --log-style semantics are used and information about the commits being merged is included in the message for the new commit. When the strategy creates a merge commit, --log=20 is used to ensure the resulting message is not oversized when a pull request merges a large number of commits.

Such a limitation is not applied to squash "merge" strategies, however, which can result in excessively large messages when a large number of commits are squashed. For example, a squash merge including 12,000+ commits can result in a commit message that is hundreds of megabytes in size. In addition to impacts on Bitbucket Server (see BSERV-10767), such messages can also cause downstream pain (for example, in build systems that use JGit to display commit details).

Similar limiting should be applied to squash "merge" messages as what is applied for other strategies that create merge commits.