From 7445d6c830d50a92e3ce6093122c2c64e8a8704e Mon Sep 17 00:00:00 2001
From: Trevor Slocum <trevor@rocketnine.space>
Date: Wed, 25 Nov 2020 21:59:12 -0800
Subject: [PATCH] Always use lowercase hostname in requests

---
 README.md                |  2 ++
 pkg/gmitohtml/convert.go | 24 +++++++++++++++++-------
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 3c19aa3..c4cb521 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,8 @@ conversion tool and daemon
 
 [**Download gmitohtml**](https://gmitohtml.rocketnine.space/download/?sort=name&order=desc)
 
+gmitohtml is available on Android as [Xenia](https://gitlab.com/tslocum/xenia).
+
 ## Compile
 
 gmitohtml is written in [Go](https://golang.org). Run the following command to
diff --git a/pkg/gmitohtml/convert.go b/pkg/gmitohtml/convert.go
index 9e7049b..36c1f24 100644
--- a/pkg/gmitohtml/convert.go
+++ b/pkg/gmitohtml/convert.go
@@ -26,25 +26,35 @@ func rewriteURL(u string, loc *url.URL) string {
 			scheme = "file"
 		}
 
-		if strings.HasPrefix(u, "gemini://") {
-			return "http://" + daemonAddress + "/gemini/" + u[9:]
-		} else if strings.HasPrefix(u, "file://") {
+		if strings.HasPrefix(u, "file://") {
 			if !allowFileAccess {
 				return "http://" + daemonAddress + "/?FileAccessNotAllowed"
 			}
 			return "http://" + daemonAddress + "/file/" + u[7:]
+		}
+
+		offset := 0
+		if strings.HasPrefix(u, "gemini://") {
+			offset = 9
+		}
+		firstSlash := strings.IndexRune(u[offset:], '/')
+		if firstSlash != -1 {
+			u = strings.ToLower(u[:firstSlash+offset]) + u[firstSlash+offset:]
+		}
+
+		if strings.HasPrefix(u, "gemini://") {
+			return "http://" + daemonAddress + "/gemini/" + u[9:]
 		} else if strings.Contains(u, "://") {
 			return u
 		} else if loc != nil && len(u) > 0 && !strings.HasPrefix(u, "//") {
-			newPath := u
 			if u[0] != '/' {
 				if loc.Path[len(loc.Path)-1] == '/' {
-					newPath = path.Join("/", loc.Path, u)
+					u = path.Join("/", loc.Path, u)
 				} else {
-					newPath = path.Join("/", path.Dir(loc.Path), u)
+					u = path.Join("/", path.Dir(loc.Path), u)
 				}
 			}
-			return "http://" + daemonAddress + "/" + scheme + "/" + loc.Host + newPath
+			return "http://" + daemonAddress + "/" + scheme + "/" + strings.ToLower(loc.Host) + u
 		}
 		return "http://" + daemonAddress + "/" + scheme + "/" + u
 	}