[libhttpseverywhere] updater: ruleset path and error handling updated

[Daniel Brendle <elbren src gnome org>]

commit f45b0dceb0526c477d6b78a8f4a657beb218ef5a
Author: grindhold <grindhold gmx net>
Date:   Wed Jan 24 19:38:41 2018 +0100

    updater: ruleset path and error handling updated
    
    corrected the path for the default rulesets file inside the archive
    additionally provide a new error that gets thrown when the appropriate
    file has not been found inside the downloaded archive

 src/update.vala |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)
---
diff --git a/src/update.vala b/src/update.vala
index bb8a9db..9168e28 100644
--- a/src/update.vala
+++ b/src/update.vala
@@ -44,6 +44,7 @@ namespace HTTPSEverywhere {
         CANT_REACH_SERVER,
         CANT_READ_HTTP_BODY,
         CANT_READ_FROM_ARCHIVE,
+        NO_RULESET_FILE,
         WRITE_FAILED
     }
 
@@ -58,6 +59,7 @@ namespace HTTPSEverywhere {
         private static string UPDATE_DIR = Path.build_filename(Environment.get_user_data_dir(),
                                                                "libhttpseverywhere");
         private const string UPDATE_URL = "https://www.eff.org/files/https-everywhere-latest.xpi";;
+        private const string RULESET_PATH = "rules/default.rulesets";
         private const string LOCK_NAME = "lock";
         private const string ETAG_NAME = "etag";
 
@@ -190,8 +192,10 @@ namespace HTTPSEverywhere {
 
             string json = "";
             unowned Archive.Entry e = null;
+            bool found_ruleset_file = false;
             while (zipreader.next_header(out e) == Archive.Result.OK) {
-                if (e != null && e.pathname() == "webextension/rules/default.rulesets") {
+                if (e != null && e.pathname() == Updater.RULESET_PATH) {
+                    found_ruleset_file = true;
                     uint8[] jsonblock = new uint8[1024*1024];
                     while (true) {
                         var r = zipreader.read_data(jsonblock, 1024*1024);
@@ -211,6 +215,10 @@ namespace HTTPSEverywhere {
                     zipreader.read_data_skip();
             }
 
+            // Throw an Exception when the expected ruleset file could not be found
+            if (!found_ruleset_file)
+                throw new UpdateError.NO_RULESET_FILE("Could not find expected ruleset file in the 
downloaded archive: %s", Updater.RULESET_PATH);
+
             // Copying the new Rules-File to the target
             update_state = UpdateState.COPYING_RULES;
             string rulesets_path = Path.build_filename(UPDATE_DIR, rulesets_file);