commit: abort on merge with missing files Here is a script illustrating the previous behaviour: The merge brings a new file 'b' from remote $ hg merge 1 --debug searching for copies back to rev 1 unmatched files in other: b resolving manifests overwrite: False, partial: False ancestor: 07f494440405, local: 540395c44225+, remote: 102a90ea7b4a b: remote created -> g updating: b 1/1 files (100.00%) getting b 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) Delete but do not remove b $ rm b $ hg st ! b The commit succeeds $ hg commit -m merge $ hg parents --template "{rev} {desc|firstline} files: {files}\n" 3 merge files: $ hg st ! b b changes were ignored, but even b existence was ignored $ hg manifest a This happens because localrepo.commitctx() checks the input ctx.files(), which is empty for workingctx.files() only returns added, modified or removed entries, and bypass files/manifest updates completely. So the committed revision manifest is the same as its first parent one, not containing the 'b' file. This patch forces the commit to abort in presence of a merge and missing files. test-merge4.t is modified accordingly as it was introduced to check hg was not just terminating with a traceback (5e9e8b8d2629).