prepush: add more precise error messages
Part of the patch is from timeless@mozdev.org
- indicate the branch name where there are multiple heads
- give better advice when hitting a possible race, where new heads are added
between discovery and the call to branchmap(). In that case, asking the user
to merge isn't helpful, since only remote has the changes.
% wide diffstat
a | 213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 213 insertions(+), 0 deletions(-)
% diffstat width
a | 213 ++++++++++++++
1 files changed, 213 insertions(+), 0 deletions(-)
% narrow diffstat
a | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
% binary diffstat
b | 0
1 files changed, 0 insertions(+), 0 deletions(-)
% binary git diffstat
b | Bin
1 files changed, 0 insertions(+), 0 deletions(-)