fix(git): Do not rely on FETCH_HEAD to list the current branch first

The `.git/FETCH_HEAD` file does not only contain a single ref for the current branch, but all refs that have been fetched last. Do not assume the entry for the current branch to be the first one, and use JGit's `FetchResult` to search for the correct resolved revision to reset to. Fixes #7725. Signed-off-by: Sebastian Schuberth <[email protected]>
oss-review-toolkit · Jan 24, 2024 · b2262a1 · b2262a1
1 parent 34859a6
commit b2262a1
Showing 1 changed file with 20 additions and 2 deletions.
diff --git a/plugins/version-control-systems/git/src/main/kotlin/Git.kt b/plugins/version-control-systems/git/src/main/kotlin/Git.kt
@@ -29,9 +29,11 @@ import org.apache.logging.log4j.kotlin.logger
 
 import org.eclipse.jgit.api.Git
 import org.eclipse.jgit.api.LsRemoteCommand
+import org.eclipse.jgit.api.ResetCommand
 import org.eclipse.jgit.api.errors.GitAPIException
 import org.eclipse.jgit.errors.UnsupportedCredentialItem
 import org.eclipse.jgit.lib.Constants
+import org.eclipse.jgit.lib.ObjectIdRef
 import org.eclipse.jgit.lib.SymbolicRef
 import org.eclipse.jgit.transport.CredentialItem
 import org.eclipse.jgit.transport.CredentialsProvider
@@ -51,6 +53,7 @@ import org.ossreviewtoolkit.utils.common.CommandLineTool
 import org.ossreviewtoolkit.utils.common.Os
 import org.ossreviewtoolkit.utils.common.collectMessages
 import org.ossreviewtoolkit.utils.common.safeMkdirs
+import org.ossreviewtoolkit.utils.common.withoutPrefix
 import org.ossreviewtoolkit.utils.ort.requestPasswordAuthentication
 import org.ossreviewtoolkit.utils.ort.showStackTrace
 
@@ -230,19 +233,34 @@ class Git : VersionControlSystem(), CommandLineTool {
             } else {
                 workingTree.runGit("fetch", "--tags", "origin")
             }
+
+            // Do a dummy fetch call to create a JGit FetchResult based on the Git CLI call.
+            git.fetch().call()
         }.onFailure {
             it.showStackTrace()
 
             logger.warn { "Failed to fetch everything: ${it.collectMessages()}" }
-        }.mapCatching {
+        }.mapCatching { fetchResult ->
             // TODO: Migrate this to JGit once sparse checkout (https://bugs.eclipse.org/bugs/show_bug.cgi?id=383772) is
             //       implemented.
             run("checkout", revision, workingDir = workingTree.workingDir)
 
             // In case of a non-fixed revision (branch or tag) reset the working tree to ensure that the previously
             // fetched changes are applied.
             if (!isFixedRevision(workingTree, revision).getOrThrow()) {
-                run("reset", "--hard", "FETCH_HEAD", workingDir = workingTree.workingDir)
+                val refs = fetchResult.advertisedRefs.filterIsInstance<ObjectIdRef>()
+
+                val tags = refs.mapNotNull { ref ->
+                    ref.name.withoutPrefix(Constants.R_TAGS)?.let { it to ref.objectId.name }
+                }.toMap()
+
+                val branches = refs.mapNotNull { ref ->
+                    ref.name.withoutPrefix(Constants.R_HEADS)?.let { it to ref.objectId.name }
+                }.toMap()
+
+                (tags[revision] ?: branches[revision])?.also { resolvedRevision ->
+                    git.reset().setMode(ResetCommand.ResetType.HARD).setRef(resolvedRevision).call()
+                }
             }
 
             revision