Git 2.0: git svn: Set default --prefix='origin/' if --prefix is not given

git-svn by default puts its Subversion-tracking refs directly in
refs/remotes/*. This runs counter to Git's convention of using
refs/remotes/$remote/* for storing remote-tracking branches.

Furthermore, combining git-svn with regular git remotes run the risk of
clobbering refs under refs/remotes (e.g. if you have a git remote
called "tags" with a "v1" branch, it will overlap with the git-svn's
tracking branch for the "v1" tag from Subversion.

Even though the git-svn refs stored in refs/remotes/* are not "proper"
remote-tracking branches (since they are not covered by a proper git
remote's refspec), they clearly represent a similar concept, and would
benefit from following the same convention.

For example, if git-svn tracks Subversion branch "foo" at
refs/remotes/foo, and you create a local branch refs/heads/foo to add
some commits to be pushed back to Subversion (using "git svn dcommit),
then it is clearly unhelpful of Git to throw

  warning: refname 'foo' is ambiguous.

every time you checkout, rebase, or otherwise interact with the branch.

The existing workaround for this is to supply the --prefix=quux/ to
git svn init/clone, so that git-svn's tracking branches end up in
refs/remotes/quux/* instead of refs/remotes/*. However, encouraging
users to specify --prefix to work around a design flaw in git-svn is
suboptimal, and not a long term solution to the problem. Instead,
git-svn should default to use a non-empty prefix that saves
unsuspecting users from the inconveniences described above.

This patch will only affect newly created git-svn setups, as the
--prefix option only applies to git svn init (and git svn clone).
Existing git-svn setups will continue with their existing (lack of)
prefix. Also, if anyone somehow prefers git-svn's old layout, they
can recreate that by explicitly passing an empty prefix (--prefix "")
on the git svn init/clone command line.

The patch changes the default value for --prefix from "" to "origin/",
updates the git-svn manual page, and fixes the fallout in the git-svn
testcases.

(Note that this patch might be easier to review using the --word-diff
and --word-diff-regex=. diff options.)

[ew: squashed description of <= 1.9 behavior into manpage]

Suggested-by: Thomas Ferris Nicolaisen <tfnico@gmail.com>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Eric Wong <normalperson@yhbt.net>

1 files changed, 23 insertions, 23 deletions

diff --git a/t/t9116-git-svn-log.sh b/t/t9116-git-svn-log.sh
index cf4c05261b..45773ee560 100755
--- a/t/t9116-git-svn-log.sh
+++ b/t/t9116-git-svn-log.sh
@@ -20,20 +20,20 @@ test_expect_success 'setup repository and import' '
 	) &&
 	git svn init "$svnrepo" -T trunk -b branches -t tags &&
 	git svn fetch &&
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	echo bye >> README &&
 	git commit -a -m bye &&
 	git svn dcommit &&
-	git reset --hard a &&
+	git reset --hard origin/a &&
 	echo why >> FEEDME &&
 	git update-index --add FEEDME &&
 	git commit -m feedme &&
 	git svn dcommit &&
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	echo aye >> README &&
 	git commit -a -m aye &&
 	git svn dcommit &&
-	git reset --hard b &&
+	git reset --hard origin/b &&
 	echo spy >> README &&
 	git commit -a -m spy &&
 	echo try >> README &&
@@ -42,26 +42,26 @@ test_expect_success 'setup repository and import' '
 	'
 
 test_expect_success 'run log' "
-	git reset --hard a &&
-	git svn log -r2 trunk | grep ^r2 &&
-	git svn log -r4 trunk | grep ^r4 &&
+	git reset --hard origin/a &&
+	git svn log -r2 origin/trunk | grep ^r2 &&
+	git svn log -r4 origin/trunk | grep ^r4 &&
 	git svn log -r3 | grep ^r3
 	"
 
 test_expect_success 'run log against a from trunk' "
-	git reset --hard trunk &&
-	git svn log -r3 a | grep ^r3
+	git reset --hard origin/trunk &&
+	git svn log -r3 origin/a | grep ^r3
 	"
 
 printf 'r1 \nr2 \nr4 \n' > expected-range-r1-r2-r4
 
 test_expect_success 'test ascending revision range' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 1:4 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r1-r2-r4 -
 	"
 
 test_expect_success 'test ascending revision range with --show-commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log --show-commit -r 1:4 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r1-r2-r4 -
 	"
 
@@ -69,7 +69,7 @@ test_expect_success 'test ascending revision range with --show-commit (sha1)' "
 	git svn find-rev r1 >expected-range-r1-r2-r4-sha1 &&
 	git svn find-rev r2 >>expected-range-r1-r2-r4-sha1 &&
 	git svn find-rev r4 >>expected-range-r1-r2-r4-sha1 &&
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log --show-commit -r 1:4 | grep '^r[0-9]' | cut -d'|' -f2 >out &&
 	git rev-parse \$(cat out) >actual &&
 	test_cmp expected-range-r1-r2-r4-sha1 actual
@@ -78,67 +78,67 @@ test_expect_success 'test ascending revision range with --show-commit (sha1)' "
 printf 'r4 \nr2 \nr1 \n' > expected-range-r4-r2-r1
 
 test_expect_success 'test descending revision range' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 4:1 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r4-r2-r1 -
 	"
 
 printf 'r1 \nr2 \n' > expected-range-r1-r2
 
 test_expect_success 'test ascending revision range with unreachable revision' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 1:3 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r1-r2 -
 	"
 
 printf 'r2 \nr1 \n' > expected-range-r2-r1
 
 test_expect_success 'test descending revision range with unreachable revision' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 3:1 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r2-r1 -
 	"
 
 printf 'r2 \n' > expected-range-r2
 
 test_expect_success 'test ascending revision range with unreachable upper boundary revision and 1 commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 2:3 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r2 -
 	"
 
 test_expect_success 'test descending revision range with unreachable upper boundary revision and 1 commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 3:2 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r2 -
 	"
 
 printf 'r4 \n' > expected-range-r4
 
 test_expect_success 'test ascending revision range with unreachable lower boundary revision and 1 commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 3:4 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r4 -
 	"
 
 test_expect_success 'test descending revision range with unreachable lower boundary revision and 1 commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 4:3 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r4 -
 	"
 
 printf -- '------------------------------------------------------------------------\n' > expected-separator
 
 test_expect_success 'test ascending revision range with unreachable boundary revisions and no commits' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 5:6 | test_cmp expected-separator -
 	"
 
 test_expect_success 'test descending revision range with unreachable boundary revisions and no commits' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 6:5 | test_cmp expected-separator -
 	"
 
 test_expect_success 'test ascending revision range with unreachable boundary revisions and 1 commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 3:5 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r4 -
 	"
 
 test_expect_success 'test descending revision range with unreachable boundary revisions and 1 commit' "
-	git reset --hard trunk &&
+	git reset --hard origin/trunk &&
 	git svn log -r 5:3 | grep '^r[0-9]' | cut -d'|' -f1 | test_cmp expected-range-r4 -
 	"