bitbake: fetch/git: Rework tag parameter handling

Currently bitbake disallows tag parameters along with revision parameters.
This isn't great since quite often, we'd like to verify that a given revision
does match some tag. At the same time we don't want to or need to access
the network to verify this, which normally a tag would require.

Rework the code so that tag and revisions can both be specified together.
Verify that any tag specified matches the revision in use at unpack time.

This means we can start requiring people to put tags in git SRC_URIs
when revisions are used, making review a little easier that it isn't
some random revision.

The test that is dropped looks like a different test but the comment
is a copy and paste error. The SRCREV/rev mismatch test remains, this
removes the rev and tag set test.

(Bitbake rev: d591d7633fe8d739ec00395920e44910b0b77e27)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 17 insertions, 14 deletions

diff --git a/bitbake/lib/bb/fetch2/__init__.py b/bitbake/lib/bb/fetch2/__init__.py
index 5aa67accc3..cfbbce5288 100644
--- a/bitbake/lib/bb/fetch2/__init__.py
+++ b/bitbake/lib/bb/fetch2/__init__.py
@@ -1248,20 +1248,17 @@ def srcrev_internal_helper(ud, d, name):
         if srcrev and srcrev != "INVALID":
             break
 
-    if 'rev' in ud.parm and 'tag' in ud.parm:
-        raise FetchError("Please specify a ;rev= parameter or a ;tag= parameter in the url %s but not both." % (ud.url))
-
-    if 'rev' in ud.parm or 'tag' in ud.parm:
-        if 'rev' in ud.parm:
-            parmrev = ud.parm['rev']
-        else:
-            parmrev = ud.parm['tag']
+    if 'rev' in ud.parm:
+        parmrev = ud.parm['rev']
         if srcrev == "INVALID" or not srcrev:
             return parmrev
         if srcrev != parmrev:
             raise FetchError("Conflicting revisions (%s from SRCREV and %s from the url) found, please specify one valid value" % (srcrev, parmrev))
         return parmrev
 
+    if 'tag' in ud.parm and (srcrev == "INVALID" or not srcrev):
+        return ud.parm['tag']
+
     if srcrev == "INVALID" or not srcrev:
         raise FetchError("Please set a valid SRCREV for url %s (possible key names are %s, or use a ;rev=X URL parameter)" % (str(attempts), ud.url), ud.url)
     if srcrev == "AUTOINC":
diff --git a/bitbake/lib/bb/fetch2/git.py b/bitbake/lib/bb/fetch2/git.py
index a73fb79ac8..53fdc4c3df 100644
--- a/bitbake/lib/bb/fetch2/git.py
+++ b/bitbake/lib/bb/fetch2/git.py
@@ -279,6 +279,10 @@ class Git(FetchMethod):
                     ud.unresolvedrev[name] = ud.revisions[name]
                 ud.revisions[name] = self.latest_revision(ud, d, name)
 
+        if 'tag' in ud.parm:
+            if len(ud.revisions) != 1:
+                raise bb.fetch2.ParameterError("Git fetcher support for multiple tagged revisions not implemented", ud.url)
+
         gitsrcname = '%s%s' % (ud.host.replace(':', '.'), ud.path.replace('/', '.').replace('*', '.').replace(' ','_').replace('(', '_').replace(')', '_'))
         if gitsrcname.startswith('.'):
             gitsrcname = gitsrcname[1:]
@@ -747,6 +751,14 @@ class Git(FetchMethod):
         if not source_found:
             raise bb.fetch2.UnpackError("No up to date source found: " + "; ".join(source_error), ud.url)
 
+        # If there is a tag parameter in the url and we also have a fixed srcrev, check the tag
+        # matches the revision
+        if 'tag' in ud.parm and sha1_re.match(ud.revision):
+            output = runfetchcmd("%s rev-list -n 1 %s" % (ud.basecmd, ud.parm['tag']), d, workdir=destdir)
+            output = output.strip()
+            if output != ud.revision:
+                raise bb.fetch2.FetchError("The revision the git tag '%s' resolved to didn't match the SRCREV in use (%s vs %s)" % (ud.parm['tag'], output, ud.revision), ud.url)
+
         repourl = self._get_repo_url(ud)
         runfetchcmd("%s remote set-url origin %s" % (ud.basecmd, shlex.quote(repourl)), d, workdir=destdir)
 
diff --git a/bitbake/lib/bb/tests/fetch.py b/bitbake/lib/bb/tests/fetch.py
index cd81660b1b..b4e9255578 100644
--- a/bitbake/lib/bb/tests/fetch.py
+++ b/bitbake/lib/bb/tests/fetch.py
@@ -1087,12 +1087,6 @@ class FetcherNetworkTest(FetcherTest):
         self.assertRaises(bb.fetch.FetchError, self.gitfetcher, url1, url2)
 
     @skipIfNoNetwork()
-    def test_gitfetch_tagandrev(self):
-        # SRCREV is set but does not match rev= parameter
-        url1 = url2 = "git://git.openembedded.org/bitbake;rev=270a05b0b4ba0959fe0624d2a4885d7b70426da5;tag=270a05b0b4ba0959fe0624d2a4885d7b70426da5;protocol=https;branch=master"
-        self.assertRaises(bb.fetch.FetchError, self.gitfetcher, url1, url2)
-
-    @skipIfNoNetwork()
     def test_gitfetch_usehead(self):
         # Since self.gitfetcher() sets SRCREV we expect this to override
         # `usehead=1' and instead fetch the specified SRCREV. See