From: Julian Andres Klode <jak@debian.org>
Date: Mon, 17 Mar 2014 12:43:12 +0000 (+0100)
Subject: apt-inst: Do not try to create a substring of an empty string in error reporting
X-Git-Tag: 1.0~26
X-Git-Url: https://git.saurik.com/apt.git/commitdiff_plain/b68ce88357daf362e60d7f8f131041289c8db690?ds=sidebyside;hp=384c9b0d4f69aac57da8298c4252499d1f7a83ca

apt-inst: Do not try to create a substring of an empty string in error reporting

One of our compressors (the empty one) has an empty extension. Calling substr
on it fails.
---

diff --git a/apt-inst/deb/debfile.cc b/apt-inst/deb/debfile.cc
index 3803329fa..a63cb6716 100644
--- a/apt-inst/deb/debfile.cc
+++ b/apt-inst/deb/debfile.cc
@@ -124,8 +124,10 @@ bool debDebFile::ExtractTarMember(pkgDirStream &Stream,const char *Name)
    {
       std::string ext = std::string(Name) + ".{";
       for (std::vector<APT::Configuration::Compressor>::const_iterator c = compressor.begin();
-	   c != compressor.end(); ++c)
-	 ext.append(c->Extension.substr(1));
+	   c != compressor.end(); ++c) {
+	 if (!c->Extension.empty())
+	    ext.append(c->Extension.substr(1));
+      }
       ext.append("}");
       return _error->Error(_("Internal error, could not locate member %s"), ext.c_str());
    }