From 3e151692778e19b2d435b175bf4f5d6a4483421f Mon Sep 17 00:00:00 2001
From: Laurent Demailly <ldemailly@gmail.com>
Date: Thu, 15 Aug 2024 12:14:13 -0700
Subject: [PATCH] Trying a fix for go#68880 - not yet working/enough

---
 go.mod      |  3 ++-
 go.sum      |  6 ++++--
 terminal.go | 26 +++++++++++++++++++++++++-
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/go.mod b/go.mod
index f3be8a2..adc5e4d 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,8 @@ go 1.22.6
 require (
 	fortio.org/cli v1.8.0
 	fortio.org/log v1.16.0
-	fortio.org/term v0.23.0-fortio-6
+	fortio.org/term v0.23.0-fortio-6.0.20240815191104-2119463b2839
+	github.com/rivo/uniseg v0.4.7
 )
 
 // replace fortio.org/term => ../term
diff --git a/go.sum b/go.sum
index cc7bc67..8e70df4 100644
--- a/go.sum
+++ b/go.sum
@@ -4,12 +4,14 @@ fortio.org/log v1.16.0 h1:GhU8/9NkYZmEIzvTN/DTMedDAStLJraWUUVUA2EbNDc=
 fortio.org/log v1.16.0/go.mod h1:t58Spg9njjymvRioh5F6qKGSupEsnMjXLGWIS1i3khE=
 fortio.org/struct2env v0.4.1 h1:rJludAMO5eBvpWplWEQNqoVDFZr4RWMQX7RUapgZyc0=
 fortio.org/struct2env v0.4.1/go.mod h1:lENUe70UwA1zDUCX+8AsO663QCFqYaprk5lnPhjD410=
-fortio.org/term v0.23.0-fortio-6 h1:pKrUX0tKOxyEhkhLV50oJYucTVx94rzFrXc24lIuLvk=
-fortio.org/term v0.23.0-fortio-6/go.mod h1:7buBfn81wEJUGWiVjFNiUE/vxWs5FdM9c7PyZpZRS30=
+fortio.org/term v0.23.0-fortio-6.0.20240815191104-2119463b2839 h1:O5K8+QX6oosCALDvcD8MmUS+IPThkuyKhQDRocCvNJ0=
+fortio.org/term v0.23.0-fortio-6.0.20240815191104-2119463b2839/go.mod h1:7buBfn81wEJUGWiVjFNiUE/vxWs5FdM9c7PyZpZRS30=
 fortio.org/version v1.0.4 h1:FWUMpJ+hVTNc4RhvvOJzb0xesrlRmG/a+D6bjbQ4+5U=
 fortio.org/version v1.0.4/go.mod h1:2JQp9Ax+tm6QKiGuzR5nJY63kFeANcgrZ0osoQFDVm0=
 github.com/kortschak/goroutine v1.1.2 h1:lhllcCuERxMIK5cYr8yohZZScL1na+JM5JYPRclWjck=
 github.com/kortschak/goroutine v1.1.2/go.mod h1:zKpXs1FWN/6mXasDQzfl7g0LrGFIOiA6cLs9eXKyaMY=
+github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
+github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 golang.org/x/crypto/x509roots/fallback v0.0.0-20240806160748-b2d3a6a4b4d3 h1:oWb21rU9Q9XrRwXLB7jHc1rbp6EiiimZZv5MLxpu4T0=
 golang.org/x/crypto/x509roots/fallback v0.0.0-20240806160748-b2d3a6a4b4d3/go.mod h1:kNa9WdvYnzFwC79zRpLRMJbdEFlhyM5RPFBBZp/wWH8=
 golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
diff --git a/terminal.go b/terminal.go
index 7588075..4a06e45 100644
--- a/terminal.go
+++ b/terminal.go
@@ -11,8 +11,31 @@ import (
 
 	"fortio.org/log"
 	"fortio.org/term"
+	"github.com/rivo/uniseg"
 )
 
+func VisualLength(runes []rune) int {
+	filtered := make([]rune, 0, len(runes))
+	inEscapeSeq := false
+	// Skip escape sequences.
+	for _, r := range runes {
+		switch {
+		// Copied from term's visualLength
+		case inEscapeSeq:
+			if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') {
+				inEscapeSeq = false
+			}
+		case r == '\x1b':
+			inEscapeSeq = true
+		default:
+			filtered = append(filtered, r)
+		}
+	}
+	l := uniseg.StringWidth(string(filtered))
+	//	fmt.Printf("\nVisualLength(%q) = %d\n", string(runes), l)
+	return l
+}
+
 type Terminal struct {
 	// Use this for any output to the screen/console so the required \r are added in raw mode
 	// the prompt and command edit is refresh as needed when input comes in.
@@ -38,6 +61,7 @@ func Open() (*Terminal, error) {
 		fd: int(os.Stdin.Fd()),
 	}
 	t.term = term.NewTerminal(rw, "")
+	t.term.VisualLength = VisualLength
 	t.Out = t.term
 	if !t.IsTerminal() {
 		t.Out = os.Stderr // no need to add \r for non raw mode.
@@ -216,7 +240,7 @@ func (t *Terminal) Close() error {
 		return nil
 	}
 	h := t.term.History()
-	log.LogVf("got history %v", h)
+	// log.LogVf("got history %v", h)
 	slices.Reverse(h)
 	extra := len(h) - t.capacity
 	if extra > 0 {