cachefile: Only set members that were initialized successfully

Otherwise, things will just start failing later down the stack,
because (a) the lazy getters do not check if building was successful
and (b) any further getter call would return the invalid object
anyway.

Also initialize VS in pkgCache to nullptr by default.

Closes: #818628

1 files changed, 46 insertions, 16 deletions

diff --git a/apt-pkg/cachefile.cc b/apt-pkg/cachefile.cc
index 909da5cb4..0e2192973 100644
--- a/apt-pkg/cachefile.cc
+++ b/apt-pkg/cachefile.cc
@@ -32,6 +32,7 @@
 #include <unistd.h>
 #include <string>
 #include <vector>
+#include <memory>
 
 #include <apti18n.h>
 									/*}}}*/
@@ -69,9 +70,13 @@ public:
    ScopedErrorMerge() { _error->PushToStack(); }
    ~ScopedErrorMerge() { _error->MergeWithStack(); }
 };
+
 bool pkgCacheFile::BuildCaches(OpProgress *Progress, bool WithLock)
 {
-   if (Cache != NULL)
+   std::unique_ptr<pkgCache> Cache;
+   std::unique_ptr<MMap> Map;
+
+   if (this->Cache != NULL)
       return true;
 
    ScopedErrorMerge sem;
@@ -80,11 +85,16 @@ bool pkgCacheFile::BuildCaches(OpProgress *Progress, bool WithLock)
       FileFd file(_config->FindFile("Dir::Cache::pkgcache"), FileFd::ReadOnly);
       if (file.IsOpen() == false || file.Failed())
 	 return false;
-      Map = new MMap(file, MMap::Public|MMap::ReadOnly);
+      Map.reset(new MMap(file, MMap::Public|MMap::ReadOnly));
       if (unlikely(Map->validData() == false))
 	 return false;
-      Cache = new pkgCache(Map);
-      return _error->PendingError() == false;
+      Cache.reset(new pkgCache(Map.get()));
+      if (_error->PendingError() == true)
+	 return false;
+
+      this->Cache = Cache.release();
+      this->Map = Map.release();
+      return true;
    }
 
    if (WithLock == true)
@@ -94,11 +104,15 @@ bool pkgCacheFile::BuildCaches(OpProgress *Progress, bool WithLock)
    if (_error->PendingError() == true)
       return false;
 
-   BuildSourceList(Progress);
+   if (BuildSourceList(Progress) == false)
+      return false;
 
    // Read the caches
-   Cache = nullptr;
-   bool Res = pkgCacheGenerator::MakeStatusCache(*SrcList,Progress,&Map, &Cache, true);
+   MMap *TmpMap = nullptr;
+   pkgCache *TmpCache = nullptr;
+   bool Res = pkgCacheGenerator::MakeStatusCache(*SrcList,Progress,&TmpMap, &TmpCache, true);
+   Map.reset(TmpMap);
+   Cache.reset(TmpCache);
    if (Progress != NULL)
       Progress->Done();
    if (Res == false)
@@ -109,9 +123,12 @@ bool pkgCacheFile::BuildCaches(OpProgress *Progress, bool WithLock)
       _error->Warning(_("You may want to run apt-get update to correct these problems"));
 
    if (Cache == nullptr)
-      Cache = new pkgCache(Map);
+      Cache.reset(new pkgCache(Map.get()));
    if (_error->PendingError() == true)
       return false;
+   this->Map = Map.release();
+   this->Cache = Cache.release();
+
    return true;
 }
 									/*}}}*/
@@ -120,12 +137,14 @@ bool pkgCacheFile::BuildCaches(OpProgress *Progress, bool WithLock)
 /* */
 bool pkgCacheFile::BuildSourceList(OpProgress * /*Progress*/)
 {
-   if (SrcList != NULL)
+   std::unique_ptr<pkgSourceList> SrcList;
+   if (this->SrcList != NULL)
       return true;
 
-   SrcList = new pkgSourceList();
+   SrcList.reset(new pkgSourceList());
    if (SrcList->ReadMainList() == false)
       return _error->Error(_("The list of sources could not be read."));
+   this->SrcList = SrcList.release();
    return true;
 }
 									/*}}}*/
@@ -134,16 +153,18 @@ bool pkgCacheFile::BuildSourceList(OpProgress * /*Progress*/)
 /* */
 bool pkgCacheFile::BuildPolicy(OpProgress * /*Progress*/)
 {
-   if (Policy != NULL)
+   std::unique_ptr<pkgPolicy> Policy;
+   if (this->Policy != NULL)
       return true;
 
-   Policy = new pkgPolicy(Cache);
+   Policy.reset(new pkgPolicy(Cache));
    if (_error->PendingError() == true)
       return false;
 
    if (ReadPinFile(*Policy) == false || ReadPinDir(*Policy) == false)
       return false;
 
+   this->Policy = Policy.release();
    return true;
 }
 									/*}}}*/
@@ -152,17 +173,21 @@ bool pkgCacheFile::BuildPolicy(OpProgress * /*Progress*/)
 /* */
 bool pkgCacheFile::BuildDepCache(OpProgress *Progress)
 {
-   if (DCache != NULL)
+   std::unique_ptr<pkgDepCache> DCache;
+   if (this->DCache != NULL)
       return true;
 
    if (BuildPolicy(Progress) == false)
       return false;
 
-   DCache = new pkgDepCache(Cache,Policy);
+   DCache.reset(new pkgDepCache(Cache,Policy));
    if (_error->PendingError() == true)
       return false;
+   if (DCache->Init(Progress) == false)
+      return false;
 
-   return DCache->Init(Progress);
+   this->DCache = DCache.release();
+   return true;
 }
 									/*}}}*/
 // CacheFile::Open - Open the cache files, creating if necessary	/*{{{*/
@@ -225,7 +250,12 @@ bool pkgCacheFile::AddIndexFile(pkgIndexFile * const File)		/*{{{*/
 	       return false;
 	 }
 	 Cache = new pkgCache(Map);
-	 return _error->PendingError() == false;
+	 if (_error->PendingError() == true) {
+	    delete Cache;
+	    Cache = nullptr;
+	    return false;
+	 }
+	 return true;
       }
       else
       {