Try another change

Author: tbcrawford

src/functionalTest/kotlin/com/figure/gradle/semver/specs/CrossRepositoryPullRequestSpec.kt

@@ -71,4 +71,57 @@ class CrossRepositoryPullRequestSpec : FunSpec({
             projects.versions shouldOnlyHave "1.0.1-fix-builds-fail-cross-repo.0"
         }
     }
+
+    test("should handle cross-repo PR with both GITHUB_HEAD_REF and GITHUB_REF_NAME set") {
+        withEnvironment(
+            environment = mapOf(
+                Env.CI to "true",
+                Env.GITHUB_HEAD_REF to forkedFeatureBranch,
+                Env.GITHUB_REF_NAME to "123/merge", // Typical PR merge ref
+            ),
+            mode = OverrideMode.SetOrOverride,
+        ) {
+            // Given: Similar setup but with both environment variables set
+            projects.git {
+                initialBranch = mainBranch
+                actions = actions {
+                    commit(message = "1 commit on $mainBranch", tag = "1.0.0")
+                    checkout(mainBranch) // Stay on main to simulate cross-repo PR checkout
+                }
+            }
+
+            // When: Building should prioritize GITHUB_HEAD_REF over GITHUB_REF_NAME
+            projects.build(GradleVersion.current())
+
+            // Then: Should use the forked branch name, not the merge ref
+            projects.versions shouldOnlyHave "1.0.1-fix-builds-fail-cross-repo.0"
+        }
+    }
+
+    test("should fallback to GITHUB_REF_NAME when GITHUB_HEAD_REF is empty") {
+        withEnvironment(
+            environment = mapOf(
+                Env.CI to "true",
+                Env.GITHUB_HEAD_REF to "", // Empty but present
+                Env.GITHUB_REF_NAME to "feature-branch-fallback",
+            ),
+            mode = OverrideMode.SetOrOverride,
+        ) {
+            // Given: GITHUB_HEAD_REF is empty (not a PR) but GITHUB_REF_NAME is set
+            projects.git {
+                initialBranch = mainBranch
+                actions = actions {
+                    commit(message = "1 commit on $mainBranch", tag = "1.0.0")
+                    checkout("feature-branch-fallback")
+                    commit(message = "1 commit on feature branch")
+                }
+            }
+
+            // When: Building should use GITHUB_REF_NAME since GITHUB_HEAD_REF is empty
+            projects.build(GradleVersion.current())
+
+            // Then: Should use the ref name from GITHUB_REF_NAME with correct commit count
+            projects.versions shouldOnlyHave "1.0.1-feature-branch-fallback.1"
+        }
+    }
 })

src/main/kotlin/com/figure/gradle/semver/internal/command/Branch.kt

@@ -41,13 +41,16 @@ class Branch(
             }
 
             // Handle cross-repo PRs where the branch doesn't exist locally
-            // but we still want to use the branch name from GITHUB_HEAD_REF
-            return if (Env.isCI && Env.githubHeadRef != null && refName == Env.githubHeadRef) {
+            // This happens when GitHub Actions checks out the target repository but the
+            // branch name from GITHUB_HEAD_REF (from forked repo) doesn't exist locally
+            return if (Env.isCI && Env.githubHeadRef != null) {
                 // Create a synthetic ref object that preserves the original branch name
-                SyntheticRef(name = "refs/heads/$refName", target = headRef.objectId)
+                // This ensures version calculation uses the actual feature branch name
+                // instead of falling back to HEAD or the merge ref
+                SyntheticRef(name = "refs/heads/${Env.githubHeadRef}", target = headRef.objectId)
             } else {
-                headRef.takeIf { !it.target.name.startsWith("refs/heads/") }
-                    ?: headRef
+                // For non-CI environments or when not in a PR, use HEAD
+                headRef
             }
         }