Read and work with canonical file-URIs from sources.lists

We allow file (and other file-based methods) URIs to either be given
as file:///path or as file:/path, but in various places of the acquire
system we perform string comparisons on URIs which do not handle this
expecting the canonical representation produced by our URI code.

That used to be hidden by us quoting and dequoting the URIs in the
system, but as we don't do this anymore we have to be a bit more careful
on input.

Ideally we would do less of these comparisons, but for now lets be
content with inserting a canonicalisation early on to prevent hangs in
the acquire system.

1 files changed, 5 insertions, 5 deletions

diff --git a/apt-pkg/sourcelist.cc b/apt-pkg/sourcelist.cc
index cd7dbce9c..0ac59fcfc 100644
--- a/apt-pkg/sourcelist.cc
+++ b/apt-pkg/sourcelist.cc
@@ -85,12 +85,12 @@ bool pkgSourceList::Type::FixupURI(string &URI) const
    if (URI.find(':') == string::npos)
       return false;
 
-   URI = SubstVar(URI,"$(ARCH)",_config->Find("APT::Architecture"));
-   
+   URI = ::URI{SubstVar(URI, "$(ARCH)", _config->Find("APT::Architecture"))};
+
    // Make sure that the URI is / postfixed
-   if (URI[URI.size() - 1] != '/')
-      URI += '/';
-   
+   if (URI.back() != '/')
+      URI.push_back('/');
+
    return true;
 }
 									/*}}}*/