ftparchive/writer.cc: use a std::vector instead of hardcoded array

Arrays with predefined lengths are very fragile as they are
likely forgotten in future changes and the size in this case
is dynamic making it even more dangerous.

(cherry-picked from commit eb0d90f08d6a6f2ee334a94f8fb45c776f5bcd6e)
LP: #1817048

1 files changed, 39 insertions, 41 deletions

diff --git a/ftparchive/writer.cc b/ftparchive/writer.cc
index 153c4fb42..cf51b2603 100644
--- a/ftparchive/writer.cc
+++ b/ftparchive/writer.cc
@@ -54,14 +54,15 @@ FTWScanner *FTWScanner::Owner;
 // SetTFRewriteData - Helper for setting rewrite lists			/*{{{*/
 // ---------------------------------------------------------------------
 /* */
-inline void SetTFRewriteData(struct TFRewriteData &tfrd,
-			     const char *tag,
+static inline TFRewriteData SetTFRewriteData(const char *tag,
 			     const char *rewrite,
 			     const char *newtag = 0)
 {
-    tfrd.Tag = tag;
-    tfrd.Rewrite = rewrite;
-    tfrd.NewTag = newtag;
+   TFRewriteData tfrd;
+   tfrd.Tag = tag;
+   tfrd.Rewrite = rewrite;
+   tfrd.NewTag = newtag;
+   return tfrd;
 }
 									/*}}}*/
 
@@ -450,30 +451,28 @@ bool PackagesWriter::DoPackage(string FileName)
    }
 
    // This lists all the changes to the fields we are going to make.
-   // (7 hardcoded + maintainer + suggests + end marker)
-   TFRewriteData Changes[6+2+OverItem->FieldOverride.size()+1+1];
+   std::vector<TFRewriteData> Changes;
 
-   unsigned int End = 0;
-   SetTFRewriteData(Changes[End++], "Size", Size);
+   Changes.push_back(SetTFRewriteData("Size", Size));
    if (DoMD5 == true)
-      SetTFRewriteData(Changes[End++], "MD5sum", Db.MD5Res.c_str());
+      Changes.push_back(SetTFRewriteData("MD5sum", Db.MD5Res.c_str()));
    if (DoSHA1 == true)
-      SetTFRewriteData(Changes[End++], "SHA1", Db.SHA1Res.c_str());
+      Changes.push_back(SetTFRewriteData("SHA1", Db.SHA1Res.c_str()));
    if (DoSHA256 == true)
-      SetTFRewriteData(Changes[End++], "SHA256", Db.SHA256Res.c_str());
+      Changes.push_back(SetTFRewriteData("SHA256", Db.SHA256Res.c_str()));
    if (DoSHA512 == true)
-      SetTFRewriteData(Changes[End++], "SHA512", Db.SHA512Res.c_str());
-   SetTFRewriteData(Changes[End++], "Filename", NewFileName.c_str());
-   SetTFRewriteData(Changes[End++], "Priority", OverItem->Priority.c_str());
-   SetTFRewriteData(Changes[End++], "Status", 0);
-   SetTFRewriteData(Changes[End++], "Optional", 0);
+      Changes.push_back(SetTFRewriteData("SHA512", Db.SHA512Res.c_str()));
+   Changes.push_back(SetTFRewriteData("Filename", NewFileName.c_str()));
+   Changes.push_back(SetTFRewriteData("Priority", OverItem->Priority.c_str()));
+   Changes.push_back(SetTFRewriteData("Status", 0));
+   Changes.push_back(SetTFRewriteData("Optional", 0));
 
    string DescriptionMd5;
    if (LongDescription == false) {
       MD5Summation descmd5;
       descmd5.Add(desc.c_str());
       DescriptionMd5 = descmd5.Result().Value();
-      SetTFRewriteData(Changes[End++], "Description-md5", DescriptionMd5.c_str());
+      Changes.push_back(SetTFRewriteData("Description-md5", DescriptionMd5.c_str()));
       if (TransWriter != NULL)
 	 TransWriter->DoPackage(Package, desc, DescriptionMd5);
    }
@@ -488,12 +487,12 @@ bool PackagesWriter::DoPackage(string FileName)
 	 NewLine(1);
 	 ioprintf(c1out, _("  %s maintainer is %s not %s\n"),
 	       Package.c_str(), Tags.FindS("Maintainer").c_str(), OverItem->OldMaint.c_str());
-      }      
+      }
    }
-   
+
    if (NewMaint.empty() == false)
-      SetTFRewriteData(Changes[End++], "Maintainer", NewMaint.c_str());
-   
+      Changes.push_back(SetTFRewriteData("Maintainer", NewMaint.c_str()));
+
    /* Get rid of the Optional tag. This is an ugly, ugly, ugly hack that
       dpkg-scanpackages does. Well sort of. dpkg-scanpackages just does renaming
       but dpkg does this append bit. So we do the append bit, at least that way the
@@ -504,17 +503,17 @@ bool PackagesWriter::DoPackage(string FileName)
    {
       if (Tags.FindS("Suggests").empty() == false)
 	 OptionalStr = Tags.FindS("Suggests") + ", " + OptionalStr;
-      SetTFRewriteData(Changes[End++], "Suggests", OptionalStr.c_str());
+      Changes.push_back(SetTFRewriteData("Suggests", OptionalStr.c_str()));
    }
 
-   for (map<string,string>::const_iterator I = OverItem->FieldOverride.begin(); 
+   for (map<string,string>::const_iterator I = OverItem->FieldOverride.begin();
         I != OverItem->FieldOverride.end(); ++I)
-      SetTFRewriteData(Changes[End++],I->first.c_str(),I->second.c_str());
+      Changes.push_back(SetTFRewriteData(I->first.c_str(),I->second.c_str()));
 
-   SetTFRewriteData(Changes[End++], 0, 0);
+   Changes.push_back(SetTFRewriteData( 0, 0));
 
    // Rewrite and store the fields.
-   if (TFRewrite(Output,Tags,TFRewritePackageOrder,Changes) == false)
+   if (TFRewrite(Output,Tags,TFRewritePackageOrder,Changes.data()) == false)
       return false;
    fprintf(Output,"\n");
 
@@ -827,22 +826,21 @@ bool SourcesWriter::DoPackage(string FileName)
 
    // This lists all the changes to the fields we are going to make.
    // (5 hardcoded + checksums + maintainer + end marker)
-   TFRewriteData Changes[5+2+1+SOverItem->FieldOverride.size()+1];
+   std::vector<TFRewriteData> Changes;
 
-   unsigned int End = 0;
-   SetTFRewriteData(Changes[End++],"Source",Package.c_str(),"Package");
+   Changes.push_back(SetTFRewriteData("Source",Package.c_str(),"Package"));
    if (Files.empty() == false)
-      SetTFRewriteData(Changes[End++],"Files",Files.c_str());
+      Changes.push_back(SetTFRewriteData("Files",Files.c_str()));
    if (ChecksumsSha1.empty() == false)
-      SetTFRewriteData(Changes[End++],"Checksums-Sha1",ChecksumsSha1.c_str());
+      Changes.push_back(SetTFRewriteData("Checksums-Sha1",ChecksumsSha1.c_str()));
    if (ChecksumsSha256.empty() == false)
-      SetTFRewriteData(Changes[End++],"Checksums-Sha256",ChecksumsSha256.c_str());
+      Changes.push_back(SetTFRewriteData("Checksums-Sha256",ChecksumsSha256.c_str()));
    if (ChecksumsSha512.empty() == false)
-      SetTFRewriteData(Changes[End++],"Checksums-Sha512",ChecksumsSha512.c_str());
+      Changes.push_back(SetTFRewriteData("Checksums-Sha512",ChecksumsSha512.c_str()));
    if (Directory != "./")
-      SetTFRewriteData(Changes[End++],"Directory",Directory.c_str());
-   SetTFRewriteData(Changes[End++],"Priority",BestPrio.c_str());
-   SetTFRewriteData(Changes[End++],"Status",0);
+      Changes.push_back(SetTFRewriteData("Directory",Directory.c_str()));
+   Changes.push_back(SetTFRewriteData("Priority",BestPrio.c_str()));
+   Changes.push_back(SetTFRewriteData("Status",0));
 
    // Rewrite the maintainer field if necessary
    bool MaintFailed;
@@ -857,16 +855,16 @@ bool SourcesWriter::DoPackage(string FileName)
       }      
    }
    if (NewMaint.empty() == false)
-      SetTFRewriteData(Changes[End++], "Maintainer", NewMaint.c_str());
+      Changes.push_back(SetTFRewriteData("Maintainer", NewMaint.c_str()));
    
    for (map<string,string>::const_iterator I = SOverItem->FieldOverride.begin(); 
         I != SOverItem->FieldOverride.end(); ++I)
-      SetTFRewriteData(Changes[End++],I->first.c_str(),I->second.c_str());
+      Changes.push_back(SetTFRewriteData(I->first.c_str(),I->second.c_str()));
 
-   SetTFRewriteData(Changes[End++], 0, 0);
+   Changes.push_back(SetTFRewriteData(0, 0));
       
    // Rewrite and store the fields.
-   if (TFRewrite(Output,Tags,TFRewriteSourceOrder,Changes) == false)
+   if (TFRewrite(Output,Tags,TFRewriteSourceOrder,Changes.data()) == false)
       return false;
    fprintf(Output,"\n");