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

mkdir t
cd t
hg init
echo "added file1" > file1
echo "another line of text" >> file1
echo "added file2" > file2
hg add file1 file2
hg commit -m "added file1 and file2" -d "0 0" -u user
echo "changed file1" >> file1
hg commit -m "changed file1" -d "0 0" -u user
hg -q log
hg id
hg update -C 0
hg id
echo "changed file1" >> file1
hg id
hg revert
hg diff
hg status
hg id
hg update
hg diff
hg status
hg id
hg update -C 0
echo "changed file1 different" >> file1
HGMERGE=merge hg update
hg diff | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" -e "s/\(<<<<<<<\) .*/\1/" \
              -e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/" -e "s/\(>>>>>>>\) .*/\1/"
hg status
hg id
hg revert
hg diff
hg status
hg id
hg revert -r tip
hg diff
hg status
hg id
hg update -C
hg diff
hg status
hg id
cd ..; /bin/rm -rf t