rework some code to fix some scan-build warnings

No visible functional changes, just code moved around and additional
checks to eliminate impossible branches

Reported-By: scan-build
Git-Dch: Ignore

apt-pkg/aptconfiguration.cc

@@ -141,7 +141,7 @@ std::vector<std::string> const Configuration::getLanguages(bool const &All,
 	// so they will be all included in the Cache.
 	std::vector<string> builtin;
 	DIR *D = opendir(_config->FindDir("Dir::State::lists").c_str());
-	if (D != 0) {
+	if (D != NULL) {
 		builtin.push_back("none");
 		for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D)) {
 			string const name = SubstVar(Ent->d_name, "%5f", "_");
@@ -166,8 +166,8 @@ std::vector<std::string> const Configuration::getLanguages(bool const &All,
 				continue;
 			builtin.push_back(c);
 		}
+		closedir(D);
 	}
-	closedir(D);
 
 	// FIXME: Remove support for the old APT::Acquire::Translation
 	// it was undocumented and so it should be not very widthly used

apt-pkg/cacheset.cc

@@ -73,6 +73,8 @@ bool PackageContainerInterface::FromTask(PackageContainerInterface * const pci,
 		const char *start, *end;
 		parser.GetRec(start,end);
 		unsigned int const length = end - start;
+		if (unlikely(length == 0))
+		   continue;
 		char buf[length];
 		strncpy(buf, start, length);
 		buf[length-1] = '\0';

apt-pkg/contrib/gpgv.cc

@@ -103,12 +103,12 @@ void ExecGPGV(std::string const &File, std::string const &FileGPG,
       }
    }
 
+   enum  { DETACHED, CLEARSIGNED } releaseSignature = (FileGPG != File) ? DETACHED : CLEARSIGNED;
    std::vector<std::string> dataHeader;
    char * sig = NULL;
    char * data = NULL;
 
-   // file with detached signature
-   if (FileGPG != File)
+   if (releaseSignature == DETACHED)
    {
       Args.push_back(FileGPG.c_str());
       Args.push_back(File.c_str());
@@ -181,7 +181,7 @@ void ExecGPGV(std::string const &File, std::string const &FileGPG,
       putenv((char *)"LC_MESSAGES=");
    }
 
-   if (FileGPG != File)
+   if (releaseSignature == DETACHED)
    {
       execvp(gpgvpath.c_str(), (char **) &Args[0]);
       ioprintf(std::cerr, "Couldn't execute %s to check %s", Args[0], File.c_str());

apt-pkg/contrib/mmap.cc

@@ -352,6 +352,12 @@ unsigned long DynamicMMap::RawAllocate(unsigned long long Size,unsigned long Aln
    size in the file. */
 unsigned long DynamicMMap::Allocate(unsigned long ItemSize)
 {
+   if (unlikely(ItemSize == 0))
+   {
+      _error->Fatal("Can't allocate an item of size zero");
+      return 0;
+   }
+
    // Look for a matching pool entry
    Pool *I;
    Pool *Empty = 0;
@@ -412,7 +418,7 @@ unsigned long DynamicMMap::WriteString(const char *String,
 
    unsigned long const Result = RawAllocate(Len+1,0);
 
-   if (Result == 0 && _error->PendingError())
+   if (Base == NULL || (Result == 0 && _error->PendingError()))
       return 0;
 
    memcpy((char *)Base + Result,String,Len);

ftparchive/contents.cc

@@ -233,7 +233,7 @@ void GenContents::Add(const char *Dir,const char *Package)
    
    // The final component if it does not have a trailing /
    if (I - Start >= 1)
-      Root = Grab(Root,Start,Package);
+      Grab(Root,Start,Package);
 }
 									/*}}}*/
 // GenContents::WriteSpace - Write a given number of white space chars	/*{{{*/

ftparchive/override.cc

@@ -52,45 +52,41 @@ bool Override::ReadOverride(string const &File,bool const &Source)
       if (*Pkg == 0)
 	 continue;
 
+#define APT_FIND_NEXT_FIELD \
+      for (End++; isspace(*End) != 0 && *End != 0; ++End) \
+	 /* skip spaces */ ; \
+      Start = End; \
+      for (; isspace(*End) == 0 && *End != 0; ++End) \
+	 /* find end of word */ ;
+
+#define APT_WARNING_MALFORMED_LINE(FIELD) \
+      if (*End == 0) \
+      { \
+	 _error->Warning(_("Malformed override %s line %llu (%s)"),File.c_str(), \
+			 Counter, FIELD ); \
+	 continue; \
+      } \
+      *End = 0;
+
       // Find the package and zero..
-      char *Start = Pkg;
+      char *Start;
       char *End = Pkg;
       for (; isspace(*End) == 0 && *End != 0; End++);
-      if (*End == 0)
-      {
-	 _error->Warning(_("Malformed override %s line %llu #1"),File.c_str(),
-			 Counter);
-	 continue;
-      }      
-      *End = 0;
+      APT_WARNING_MALFORMED_LINE("pkgname");
+
+      APT_FIND_NEXT_FIELD;
 
       // Find the priority
       if (Source == false)
       {
-	 for (End++; isspace(*End) != 0 && *End != 0; End++);
-	 Start = End;
-	 for (; isspace(*End) == 0 && *End != 0; End++);
-	 if (*End == 0)
-	 {
-	    _error->Warning(_("Malformed override %s line %llu #2"),File.c_str(),
-			    Counter);
-	    continue;
-	 }
-	 *End = 0;
+	 APT_WARNING_MALFORMED_LINE("priority");
 	 Itm.Priority = Start;
+
+	 APT_FIND_NEXT_FIELD;
       }
-      
+
       // Find the Section
-      for (End++; isspace(*End) != 0 && *End != 0; End++);
-      Start = End;
-      for (; isspace(*End) == 0 && *End != 0; End++);
-      if (*End == 0)
-      {
-	 _error->Warning(_("Malformed override %s line %llu #3"),File.c_str(),
-			 Counter);
-	 continue;
-      }      
-      *End = 0;
+      APT_WARNING_MALFORMED_LINE("section");
       Itm.FieldOverride["Section"] = Start;
 
       // Source override files only have the two columns
@@ -99,7 +95,7 @@ bool Override::ReadOverride(string const &File,bool const &Source)
 	 Mapping[Pkg] = Itm;
 	 continue;
       }
-      
+
       // Find the =>
       for (End++; isspace(*End) != 0 && *End != 0; End++);
       if (*End != 0)

test/libapt/parsedepends_test.cc

@@ -176,7 +176,7 @@ test:
 	equals("7.15.3~", Version);
 	equals(Null | pkgCache::Dep::Equals | pkgCache::Dep::Or, Op);
 
-	Start = debListParser::ParseDepends(Start, End, Package, Version, Op, ParseArchFlags, StripMultiArch);
+	debListParser::ParseDepends(Start, End, Package, Version, Op, ParseArchFlags, StripMultiArch);
 	if (StripMultiArch == true)
 		equals("overlord-dev", Package);
 	else