From 2fa86f850cb789bc5b154f989623adc5ee9d718b Mon Sep 17 00:00:00 2001
From: Tyler <tystuyfzand@gmail.com>
Date: Sun, 11 Jun 2017 03:52:32 -0400
Subject: [PATCH] Add semver parsing to stop overwriting of newer packages

---
 src/meow.tf/deb-simple/http.go | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/meow.tf/deb-simple/http.go b/src/meow.tf/deb-simple/http.go
index 9db6e7d..d86f75f 100644
--- a/src/meow.tf/deb-simple/http.go
+++ b/src/meow.tf/deb-simple/http.go
@@ -8,6 +8,7 @@ import (
 	"log"
 	"encoding/json"
 	"fmt"
+	"github.com/blang/semver"
 )
 
 func uploadHandler(config Conf) http.Handler {
@@ -35,6 +36,14 @@ func uploadHandler(config Conf) http.Handler {
 			return
 		}
 
+		force := false
+
+		forceStr := r.URL.Query().Get("force")
+
+		if forceStr != "" && forceStr == "true" {
+			force = true
+		}
+
 		reader, err := r.MultipartReader()
 
 		if err != nil {
@@ -109,9 +118,22 @@ func uploadHandler(config Conf) http.Handler {
 			}
 
 			if p, exists := packages[f.Info.Package]; exists {
+				v1, err1 := semver.Parse(p.Info.Version)
+				v2, err2 := semver.Parse(f.Info.Version)
+
+				if err1 == nil && err2 == nil && v1.Compare(v2) > 0 && !force {
+					// Don't replace newer package
+					httpErrorf(w, "version in old package is greater than new: %s, %s - override with \"force\"", p.Info.Version, f.Info.Version)
+					return
+				}
+
 				// Archive old file
 				log.Println("Replacing", p.Name, "with", f.Name)
-				os.Remove(p.Path)
+
+				if err := os.Remove(p.Path); err != nil {
+					httpErrorf(w, "Unable to remove old package: %s", err)
+					return
+				}
 			}
 
 			packages[f.Info.Package] = f