From 7d206e10da11c2c24ecc75fc000f2924f811b649 Mon Sep 17 00:00:00 2001
From: Heschi Kreinick <heschi@google.com>
Date: Fri, 8 Nov 2019 13:43:54 -0500
Subject: [PATCH] internal/lsp/source: start import diffs at byte 0

I assumed that f.Pos() would be the first byte of the file, but it's the
position of the package declaration. This kills the file. Just use 0.

Fixes golang/go#35458.

Change-Id: Ic77c93344c71435ef8e5624c2f2defb619139a15
Reviewed-on: https://go-review.googlesource.com/c/tools/+/206145
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
---
 internal/lsp/source/format.go                 |  2 +-
 .../lsp/testdata/imports/issue35458.go.golden | 14 ++++++++++++
 .../lsp/testdata/imports/issue35458.go.in     | 22 +++++++++++++++++++
 internal/lsp/testdata/summary.txt.golden      |  2 +-
 4 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 internal/lsp/testdata/imports/issue35458.go.golden
 create mode 100644 internal/lsp/testdata/imports/issue35458.go.in

diff --git a/internal/lsp/source/format.go b/internal/lsp/source/format.go
index c6aefeed23..6b0e409bd5 100644
--- a/internal/lsp/source/format.go
+++ b/internal/lsp/source/format.go
@@ -277,7 +277,7 @@ func trimToFirstNonImport(fset *token.FileSet, f *ast.File, src []byte) []byte {
 	if firstDecl != nil {
 		end = fset.File(f.Pos()).LineStart(fset.Position(firstDecl.Pos()).Line - 1)
 	}
-	return src[fset.Position(f.Pos()).Offset:fset.Position(end).Offset]
+	return src[0:fset.Position(end).Offset]
 }
 
 // CandidateImports returns every import that could be added to filename.
diff --git a/internal/lsp/testdata/imports/issue35458.go.golden b/internal/lsp/testdata/imports/issue35458.go.golden
new file mode 100644
index 0000000000..59aaf148ff
--- /dev/null
+++ b/internal/lsp/testdata/imports/issue35458.go.golden
@@ -0,0 +1,14 @@
+-- goimports --
+package imports //@import("package")
+
+func _() {
+	println("Hello, world!")
+}
+
+
+
+
+
+
+      
+
diff --git a/internal/lsp/testdata/imports/issue35458.go.in b/internal/lsp/testdata/imports/issue35458.go.in
new file mode 100644
index 0000000000..f9b07b8844
--- /dev/null
+++ b/internal/lsp/testdata/imports/issue35458.go.in
@@ -0,0 +1,22 @@
+    
+
+
+
+
+package imports //@import("package")
+
+
+
+
+
+
+func _() {
+	println("Hello, world!")
+}
+
+
+
+
+
+
+      
diff --git a/internal/lsp/testdata/summary.txt.golden b/internal/lsp/testdata/summary.txt.golden
index 4acd1f3adc..a875e5a8ed 100644
--- a/internal/lsp/testdata/summary.txt.golden
+++ b/internal/lsp/testdata/summary.txt.golden
@@ -9,7 +9,7 @@ CaseSensitiveCompletionsCount = 4
 DiagnosticsCount = 22
 FoldingRangesCount = 2
 FormatCount = 6
-ImportCount = 6
+ImportCount = 7
 SuggestedFixCount = 1
 DefinitionsCount = 38
 TypeDefinitionsCount = 2