handle pkgnames shorter than modifiers

[apt.git] / apt-pkg / cacheset.cc

diff --git a/apt-pkg/cacheset.cc b/apt-pkg/cacheset.cc
index d453a2bfb0f26600060284c587ac0022e7d91890..2ed6a96da2348a65cd56a0d0282e1972d67e1a96 100644 (file)
--- a/apt-pkg/cacheset.cc
+++ b/apt-pkg/cacheset.cc
@@ -391,6 +391,8 @@ bool VersionContainerInterface::FromModifierCommandLine(unsigned short &modID,
                                                        CacheSetHelper &helper) {
        Version select = NEWEST;
        std::string str = cmdline;
+       if (unlikely(str.empty() == true))
+               return false;
        bool modifierPresent = false;
        unsigned short fallback = modID;
        for (std::list<Modifier>::const_iterator mod = mods.begin();
@@ -400,8 +402,8 @@ bool VersionContainerInterface::FromModifierCommandLine(unsigned short &modID,
                size_t const alength = strlen(mod->Alias);
                switch(mod->Pos) {
                case Modifier::POSTFIX:
-                       if (str.compare(str.length() - alength, alength,
-                                       mod->Alias, 0, alength) != 0)
+                       if (str.length() <= alength ||
+                             str.compare(str.length() - alength, alength, mod->Alias, 0, alength) != 0)
                                continue;
                        str.erase(str.length() - alength);
                        modID = mod->ID;