8 files changed, 27 insertions, 1 deletions
diff --git a/src/go/build/build.go b/src/go/build/build.go
index 6991e585c3..30b5283400 100644
--- a/src/go/build/build.go
+++ b/src/go/build/build.go
@@ -813,7 +813,8 @@ Found:
 			})
 			p.InvalidGoFiles = append(p.InvalidGoFiles, name)
 		}
-		if pf.Doc != nil && p.Doc == "" {
+		// Grab the first package comment as docs, provided it is not from a test file.
+		if pf.Doc != nil && p.Doc == "" && !isTest && !isXTest {
 			p.Doc = doc.Synopsis(pf.Doc.Text())
 		}
 
diff --git a/src/go/build/build_test.go b/src/go/build/build_test.go
index ac5d2c3bb9..cb2ae3c775 100644
--- a/src/go/build/build_test.go
+++ b/src/go/build/build_test.go
@@ -395,3 +395,19 @@ func TestImportDirTarget(t *testing.T) {
 		t.Errorf("p.PkgTargetRoot == %q, p.PkgObj == %q, want non-empty", p.PkgTargetRoot, p.PkgObj)
 	}
 }
+
+// TestIssue23594 prevents go/build from regressing and populating Package.Doc
+// from comments in test files.
+func TestIssue23594(t *testing.T) {
+	// Package testdata/doc contains regular and external test files
+	// with comments attached to their package declarations. The names of the files
+	// ensure that we see the comments from the test files first.
+	p, err := ImportDir("testdata/doc", 0)
+	if err != nil {
+		t.Fatalf("could not import testdata: %v", err)
+	}
+
+	if p.Doc != "Correct" {
+		t.Fatalf("incorrectly set .Doc to %q", p.Doc)
+	}
+}
diff --git a/src/go/build/testdata/doc/a_test.go b/src/go/build/testdata/doc/a_test.go
new file mode 100644
index 0000000000..1c07b56360
--- /dev/null
+++ b/src/go/build/testdata/doc/a_test.go
@@ -0,0 +1,2 @@
+// Doc from xtests
+package doc_test
diff --git a/src/go/build/testdata/doc/b_test.go b/src/go/build/testdata/doc/b_test.go
new file mode 100644
index 0000000000..0cf1605ef3
--- /dev/null
+++ b/src/go/build/testdata/doc/b_test.go
@@ -0,0 +1 @@
+package doc_test
diff --git a/src/go/build/testdata/doc/c_test.go b/src/go/build/testdata/doc/c_test.go
new file mode 100644
index 0000000000..1025707079
--- /dev/null
+++ b/src/go/build/testdata/doc/c_test.go
@@ -0,0 +1 @@
+package doc
diff --git a/src/go/build/testdata/doc/d_test.go b/src/go/build/testdata/doc/d_test.go
new file mode 100644
index 0000000000..ec19564eb3
--- /dev/null
+++ b/src/go/build/testdata/doc/d_test.go
@@ -0,0 +1,2 @@
+// Doc from regular tests.
+package doc
diff --git a/src/go/build/testdata/doc/e.go b/src/go/build/testdata/doc/e.go
new file mode 100644
index 0000000000..1025707079
--- /dev/null
+++ b/src/go/build/testdata/doc/e.go
@@ -0,0 +1 @@
+package doc
diff --git a/src/go/build/testdata/doc/f.go b/src/go/build/testdata/doc/f.go
new file mode 100644
index 0000000000..ab1d0bc935
--- /dev/null
+++ b/src/go/build/testdata/doc/f.go
@@ -0,0 +1,2 @@
+// Correct
+package doc