view tests/test-rawcommit1 @ 990:5007e0bdeed2

Fix long-standing excessive file merges

Since switching to the multihead approach, we've been creating
excessive file-level merges where files are marked as merged with
their ancestors.

This explicitly checks at commit time whether the two parent versions
are linearly related, and if so, reduces the file check-in to a
non-merge. Then the file is compared against the remaining parent,
and, if equal, skips check-in of that file (as it's not changed).

Since we're not checking in all files that were different between
versions, we no longer need to mark so many files for merge. This
removes most of the 'm' state marking as well.

Finally, it is possible to do a tree-level merge with no file-level
changes. This will happen if one user changes file A and another
changes file B. Thus, if we have have two parents, we allow commit to
proceed even if there are no file-level changes.

#!/bin/sh
hg --debug init
echo this is a1 > a
hg add a
hg commit -m0 -d "0 0" 
echo this is b1 > b
hg add b
hg commit -m1 -d "0 0" 
hg manifest 1
echo this is c1 > c
hg rawcommit -p 1 -d "0 0" -m2 c
hg manifest 2
hg parents
rm b
hg rawcommit -p 2 -d "0 0" -m3 b
hg manifest 3
hg parents
echo this is a22 > a
hg rawcommit -p 3 -d "0 0" -m4 a
hg manifest 4
hg parents
echo this is c22 > c
hg rawcommit -p 1 -d "0 0" -m5 c
hg manifest 5
hg parents
# merge, but no files changed
hg rawcommit -p 4 -p 5 -d "0 0" -m6
hg manifest 6
hg parents
# no changes what-so-ever
hg rawcommit -p 6 -d "0 0" -m7
hg manifest 7
hg parents