CPackDeb Added several optional debian binary package fields

This fixes bugs #0011355  and 0008342.
The merged patch is a contribution from Michael Lasmanis and Petri Hodju
with some extra documentation added by the merger.

Modules/CPackDeb.cmake

@@ -62,7 +62,43 @@
 #     Default   : -
 #     May be set when invoking cpack in order to trace debug informations
 #     during CPackDeb run.
-
+# CPACK_DEBIAN_PACKAGE_PREDEPENDS
+#     Mandatory : NO
+#     Default   : -
+#     see http://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
+#     This field is like Depends, except that it also forces dpkg to complete installation of
+#     the packages named before even starting the installation of the package which declares
+#     the pre-dependency.
+# CPACK_DEBIAN_PACKAGE_ENHANCES
+#     Mandatory : NO
+#     Default   : -
+#     see http://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
+#     This field is similar to Suggests but works in the opposite direction.
+#     It is used to declare that a package can enhance the functionality of another package.
+# CPACK_DEBIAN_PACKAGE_BREAKS
+#     Mandatory : NO
+#     Default   : -
+#     see http://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
+#     When one binary package declares that it breaks another, dpkg will refuse to allow the
+#     package which declares Breaks be installed unless the broken package is deconfigured first,
+#     and it will refuse to allow the broken package to be reconfigured.
+# CPACK_DEBIAN_PACKAGE_CONFLICTS
+#     Mandatory : NO
+#     Default   : -
+#     see http://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
+#     When one binary package declares a conflict with another using a Conflicts field,
+#     dpkg will refuse to allow them to be installed on the system at the same time.
+# CPACK_DEBIAN_PACKAGE_PROVIDES
+#     Mandatory : NO
+#     Default   : -
+#     see http://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
+#     A virtual package is one which appears in the Provides control field of another package.
+# CPACK_DEBIAN_PACKAGE_REPLACES
+#     Mandatory : NO
+#     Default   : -
+#     see http://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
+#     Packages can declare in their control file that they should overwrite
+#     files in certain other packages, or completely replace other packages.
 
 #=============================================================================
 # Copyright 2007-2009 Kitware, Inc.

Source/CPack/cmCPackDebGenerator.cxx

@@ -94,6 +94,18 @@ int cmCPackDebGenerator::PackageFiles()
                               this->GetOption("CPACK_DEBIAN_PACKAGE_SUGGESTS");
   const char* debian_pkg_url =
                               this->GetOption("CPACK_DEBIAN_PACKAGE_HOMEPAGE");
+  const char* debian_pkg_predep =
+                    this->GetOption("CPACK_DEBIAN_PACKAGE_PREDEPENDS");
+  const char* debian_pkg_enhances =
+                    this->GetOption("CPACK_DEBIAN_PACKAGE_ENHANCES");
+  const char* debian_pkg_breaks =
+                    this->GetOption("CPACK_DEBIAN_PACKAGE_BREAKS");
+  const char* debian_pkg_conflicts =
+                    this->GetOption("CPACK_DEBIAN_PACKAGE_CONFLICTS");
+  const char* debian_pkg_provides =
+                    this->GetOption("CPACK_DEBIAN_PACKAGE_PROVIDES");
+  const char* debian_pkg_replaces =
+                    this->GetOption("CPACK_DEBIAN_PACKAGE_REPLACES");
 
     { // the scope is needed for cmGeneratedFileStream
     cmGeneratedFileStream out(ctlfilename.c_str());
@@ -102,22 +114,46 @@ int cmCPackDebGenerator::PackageFiles()
     out << "Section: " << debian_pkg_section << "\n";
     out << "Priority: " << debian_pkg_priority << "\n";
     out << "Architecture: " << debian_pkg_arch << "\n";
-    if(debian_pkg_dep)
+    if(debian_pkg_dep && *debian_pkg_dep)
       {
       out << "Depends: " << debian_pkg_dep << "\n";
       }
-    if(debian_pkg_rec)
+    if(debian_pkg_rec && *debian_pkg_rec)
       {
       out << "Recommends: " << debian_pkg_rec << "\n";
       }
-    if(debian_pkg_sug)
+    if(debian_pkg_sug && *debian_pkg_sug)
       {
       out << "Suggests: " << debian_pkg_sug << "\n";
       }
-    if(debian_pkg_url)
+    if(debian_pkg_url && *debian_pkg_url)
       {
       out << "Homepage: " << debian_pkg_url << "\n";
       }
+    if (debian_pkg_predep && *debian_pkg_predep)
+      {
+      out << "Pre-Depends: " << debian_pkg_predep << "\n";
+      }
+    if (debian_pkg_enhances && *debian_pkg_enhances)
+      {
+      out << "Enhances: " << debian_pkg_enhances << "\n";
+      }
+    if (debian_pkg_breaks && *debian_pkg_breaks)
+      {
+      out << "Breaks: " << debian_pkg_breaks << "\n";
+      }
+    if (debian_pkg_conflicts && *debian_pkg_conflicts)
+      {
+      out << "Conflicts: " << debian_pkg_conflicts << "\n";
+      }
+    if (debian_pkg_provides && *debian_pkg_provides)
+      {
+      out << "Provides: " << debian_pkg_provides << "\n";
+      }
+    if (debian_pkg_replaces && *debian_pkg_replaces)
+      {
+      out << "Replaces: " << debian_pkg_replaces << "\n";
+      }
     unsigned long totalSize = 0;
     {
       std::string dirName = this->GetOption("CPACK_TEMPORARY_DIRECTORY");