tests/test-merge-no-file-change.t

transaction: quietly rollback if no other changes than temporary files

If no actual change have been made, we don't really need to roll them back. We
only have to cleanup some temporary files and it seems reasonable to do that
quietly.

This will help us to use the transaction in wider context¹ without impacting the
user experience.

[1] as in Python context managers that lives longer.

  $ cat <<'EOF' >> "$HGRCPATH"
  > [extensions]
  > convert =
  > [templates]
  > l = '{rev}:{node|short} p={p1rev},{p2rev} m={manifest} f={files|json}'
  > EOF

  $ check_convert_identity () {
  >     hg convert -q "$1" "$1.converted"
  >     hg outgoing -q -R "$1.converted" "$1"
  >     if [ "$?" != 1 ]; then
  >         echo '*** BUG: hash changes on convert ***'
  >         hg log -R "$1.converted" -GTl
  >     fi
  > }

Files added at both parents:

  $ hg init added-both
  $ cd added-both
  $ touch a b c
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ hg ci -qAm2 c

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  committing files:
  b
  not reusing manifest (no file change in changelog, but manifest differs)
  committing manifest
  committing changelog
  updating the branch cache
  committed changeset 3:7aa8a293f5d97377037afc21e871e036e718d659
  $ hg log -GTl
  @    3:7aa8a293f5d9 p=2,1 m=3:8667461869a1 f=[]
  |\
  | o  2:e0ea47086fce p=0,-1 m=2:b2e5b07f9374 f=["c"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  

  $ cd ..
  $ check_convert_identity added-both

Files added at both parents, but the other removed at the merge:
(In this case, ctx.files() after the commit contains the removed file "b", but
its manifest does not differ from p1.)

  $ hg init added-both-removed-at-merge
  $ cd added-both-removed-at-merge
  $ touch a b c
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ hg ci -qAm2 c

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg rm -f b
  $ hg ci --debug -m merge
  committing files:
  committing manifest
  committing changelog
  updating the branch cache
  committed changeset 3:915745f3ca3d9d699925269474c2d0a9526e8dfa
  $ hg log -GTl
  @    3:915745f3ca3d p=2,1 m=3:8e9cf3456921 f=["b"]
  |\
  | o  2:e0ea47086fce p=0,-1 m=2:b2e5b07f9374 f=["c"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  

  $ cd ..
  $ check_convert_identity added-both

An identical file added at both parents:

  $ hg init added-identical
  $ cd added-identical
  $ touch a b
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ touch b
  $ hg ci -qAm2 b

  $ hg merge
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  committed changeset 3:de26182cd210f0c3fb175ca7616704ab963d3024
  $ hg log -GTl
  @    3:de26182cd210 p=2,1 m=1:686dbf0aeca4 f=[]
  |\
  | o  2:f00991f11eca p=0,-1 m=1:686dbf0aeca4 f=["b"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  

  $ cd ..
  $ check_convert_identity added-identical

#if execbit

An identical file added at both parents, but the flag differs. Take local:

  $ hg init flag-change-take-p1
  $ cd flag-change-take-p1
  $ touch a b
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ touch b
  $ chmod +x b
  $ hg ci -qAm2 b

  $ hg merge
  warning: cannot merge flags for b without common ancestor - keeping local flags
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ chmod +x b
  $ hg ci --debug -m merge
  committing files:
  b
  reusing manifest from p1 (listed files actually unchanged)
  committing changelog
  updating the branch cache
  committed changeset 3:c8d50407916ef8a5a97cb6e36ca9bc844a6ee13e
  $ hg log -GTl
  @    3:c8d50407916e p=2,1 m=2:36b69ba4b24b f=[]
  |\
  | o  2:99451f16b3f5 p=0,-1 m=2:36b69ba4b24b f=["b"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  
  $ hg files -vr3
           0   a
           0 x b

  $ cd ..
  $ check_convert_identity flag-change-take-p1

An identical file added at both parents, but the flag differs. Take other:

  $ hg init flag-change-take-p2
  $ cd flag-change-take-p2
  $ touch a b
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ touch b
  $ chmod +x b
  $ hg ci -qAm2 b

  $ hg merge
  warning: cannot merge flags for b without common ancestor - keeping local flags
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ chmod -x b
  $ hg ci --debug -m merge
  committing files:
  b
  committing manifest
  committing changelog
  updating the branch cache
  committed changeset 3:06a62a687d87c7d8944743dee1ee9d8c66b3f6e3
  $ hg log -GTl
  @    3:06a62a687d87 p=2,1 m=3:2a315ba1aa45 f=["b"]
  |\
  | o  2:99451f16b3f5 p=0,-1 m=2:36b69ba4b24b f=["b"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  
  $ hg files -vr3
           0   a
           0   b

  $ cd ..
  $ check_convert_identity flag-change-take-p2

#endif

An identical file added at both parents, one more file added at p2:

  $ hg init added-some-p2
  $ cd added-some-p2
  $ touch a b c
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg ci -qAm2 c
  $ hg up -q 0
  $ touch b
  $ hg ci -qAm3 b

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  committing files:
  c
  not reusing manifest (no file change in changelog, but manifest differs)
  committing manifest
  committing changelog
  updating the branch cache
  committed changeset 4:f7fbc4e4d9a8fde03ba475adad675578c8bf472d
  $ hg log -GTl
  @    4:f7fbc4e4d9a8 p=3,2 m=3:92acd5bfd716 f=[]
  |\
  | o  3:e9d9f3cc981f p=0,-1 m=1:686dbf0aeca4 f=["b"]
  | |
  o |  2:93c5529a4ec7 p=1,-1 m=2:ae25a31b30b3 f=["c"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  

  $ cd ..
  $ check_convert_identity added-some-p2

An identical file added at both parents, one more file added at p1:
(In this case, p1 manifest is reused at the merge commit, which means the
manifest DAG does not have the same shape as the changelog.)

  $ hg init added-some-p1
  $ cd added-some-p1
  $ touch a b
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ touch b c
  $ hg ci -qAm2 b
  $ hg ci -qAm3 c

  $ hg merge
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  committed changeset 4:a9f0f589a913f5a149dc10dfbd5af726977c36c4
  $ hg log -GTl
  @    4:a9f0f589a913 p=3,1 m=2:ae25a31b30b3 f=[]
  |\
  | o  3:b8dc385241b5 p=2,-1 m=2:ae25a31b30b3 f=["c"]
  | |
  | o  2:f00991f11eca p=0,-1 m=1:686dbf0aeca4 f=["b"]
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
  

  $ cd ..
  $ check_convert_identity added-some-p1

A file added at p2, a named branch created at p1:

  $ hg init named-branch-p1
  $ cd named-branch-p1
  $ touch a b
  $ hg ci -qAm0 a
  $ hg ci -qAm1 b
  $ hg up -q 0
  $ hg branch -q foo
  $ hg ci -m2

  $ hg merge default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  committing files:
  b
  not reusing manifest (no file change in changelog, but manifest differs)
  committing manifest
  committing changelog
  updating the branch cache
  committed changeset 3:fb97d83b02fd072295cfc2171f21b7d38509bfd7
  $ hg log -GT'{l} branch={branch}'
  @    3:fb97d83b02fd p=2,1 m=2:9091c64f4ea1 f=[] branch=foo
  |\
  | o  2:a3a9fa6587e5 p=0,-1 m=0:8515d4bfda76 f=[] branch=foo
  | |
  o |  1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"] branch=default
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
  

  $ cd ..
  $ check_convert_identity named-branch-p1

A file added at p1, a named branch created at p2:
(In this case, p1 manifest is reused at the merge commit, which means the
manifest DAG does not have the same shape as the changelog.)

  $ hg init named-branch-p2
  $ cd named-branch-p2
  $ touch a b
  $ hg ci -qAm0 a
  $ hg branch -q foo
  $ hg ci -m1
  $ hg up -q 0
  $ hg ci -qAm1 b

  $ hg merge foo
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  committed changeset 3:036823e24692218324d4af43b07ff89f8a000096
  $ hg log -GT'{l} branch={branch}'
  @    3:036823e24692 p=2,1 m=1:686dbf0aeca4 f=[] branch=default
  |\
  | o  2:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"] branch=default
  | |
  o |  1:da38c8e00727 p=0,-1 m=0:8515d4bfda76 f=[] branch=foo
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
  

  $ cd ..
  $ check_convert_identity named-branch-p2

A file changed once at both parents, but amended to have identical content:

  $ hg init amend-p1
  $ cd amend-p1
  $ touch a
  $ hg ci -qAm0 a
  $ echo foo > a
  $ hg ci -m1
  $ hg up -q 0
  $ echo bar > a
  $ hg ci -qm2
  $ echo foo > a
  $ hg ci -qm3 --amend

  $ hg merge
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci --debug -m merge
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  committed changeset 3:314e5bc5adf5c58ea571efabe33eedba20a201aa
  $ hg log -GT'{l} branch={branch}'
  @    3:314e5bc5adf5 p=2,1 m=1:d33ea248bd73 f=[] branch=default
  |\
  | o  2:de9c64f226a3 p=0,-1 m=1:d33ea248bd73 f=["a"] branch=default
  | |
  o |  1:6a74aec01b3c p=0,-1 m=1:d33ea248bd73 f=["a"] branch=default
  |/
  o  0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
  

  $ cd ..
  $ check_convert_identity amend-p1