From fa2704b826f95bc40651da39c3210bf76aeceda4 Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Wed, 6 Oct 2021 19:07:54 +0300
Subject: Add support for backward compatibility workarounds during package
 manifest serialization

---
 libbpkg/manifest.cxx | 46 +++++++++++++++++++++++++++++++++++++---------
 libbpkg/manifest.hxx | 29 ++++++++++++++++++++++++-----
 2 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/libbpkg/manifest.cxx b/libbpkg/manifest.cxx
index 5638d1b..ef91381 100644
--- a/libbpkg/manifest.cxx
+++ b/libbpkg/manifest.cxx
@@ -2173,8 +2173,18 @@ namespace bpkg
       {
         dependencies.push_back (move (nv));
       }
-      else if (n == "tests" || n == "examples" || n == "benchmarks")
+      // @@ TMP time to drop *-0.14.0?
+      //
+      else if (n == "tests"      || n == "tests-0.14.0"    ||
+               n == "examples"   || n == "examples-0.14.0" ||
+               n == "benchmarks" || n == "benchmarks-0.14.0")
       {
+        // Strip the '-0.14.0' suffix from the value name, if present.
+        //
+        size_t p (n.find ('-'));
+        if (p != string::npos)
+          n.resize (p);
+
         tests.push_back (move (nv));
       }
       else if (n == "location")
@@ -2664,9 +2674,11 @@ namespace bpkg
   }
 
   static void
-  serialize_package_manifest (manifest_serializer& s,
-                              const package_manifest& m,
-                              bool header_only)
+  serialize_package_manifest (
+    manifest_serializer& s,
+    const package_manifest& m,
+    bool header_only,
+    const optional<standard_version>& min_ver = nullopt)
   {
     // @@ Should we check that all non-optional values are specified ?
     // @@ Should we check that values are valid: version release is not empty,
@@ -2793,7 +2805,23 @@ namespace bpkg
         s.next ("requires", r.string ());
 
       for (const test_dependency& t: m.tests)
-        s.next (to_string (t.type), t.string ());
+      {
+        string n (to_string (t.type));
+
+        // If we generate the manifest for parsing by clients of libbpkg
+        // versions less than 0.14.0-, then replace the introduced in 0.14.0
+        // build-time tests, examples, and benchmarks values with
+        // tests-0.14.0, examples-0.14.0, and benchmarks-0.14.0,
+        // respectively. This way such clients will still be able to parse it,
+        // ignoring unknown values.
+        //
+        // @@ TMP time to drop?
+        //                                               0.14.0-
+        if (t.buildtime && min_ver && min_ver->version < 13999990001ULL)
+          n += "-0.14.0";
+
+        s.next (n, t.string ());
+      }
 
       for (const build_class_expr& e: m.builds)
         s.next ("builds", serializer::merge_comment (e.string (), e.comment));
@@ -2819,9 +2847,9 @@ namespace bpkg
   }
 
   void package_manifest::
-  serialize (serializer& s) const
+  serialize (serializer& s, const optional<standard_version>& min_ver) const
   {
-    serialize_package_manifest (s, *this, false);
+    serialize_package_manifest (s, *this, false, min_ver);
   }
 
   void package_manifest::
@@ -3035,7 +3063,7 @@ namespace bpkg
   }
 
   void pkg_package_manifests::
-  serialize (serializer& s) const
+  serialize (serializer& s, const optional<standard_version>& min_ver) const
   {
     // Serialize the package list manifest.
     //
@@ -3075,7 +3103,7 @@ namespace bpkg
       if (!p.sha256sum)
         bad_value ("no valid sha256sum");
 
-      pkg_package_manifest (s, p);
+      pkg_package_manifest (s, p, min_ver);
     }
 
     s.next ("", ""); // End of stream.
diff --git a/libbpkg/manifest.hxx b/libbpkg/manifest.hxx
index 77043b0..4aa9b73 100644
--- a/libbpkg/manifest.hxx
+++ b/libbpkg/manifest.hxx
@@ -883,8 +883,19 @@ namespace bpkg
     validate_overrides (const std::vector<butl::manifest_name_value>&,
                         const std::string& source_name);
 
+    // If the minimum libbpkg version is specified, then also apply the
+    // required backward compatibility workarounds to the serialized manifest
+    // so that clients of all libbpkg versions greater or equal to the
+    // specified version can parse it, ignoring unknown values.
+    //
+    // Note that clients of the latest major libbpkg version can fully
+    // recognize the produced manifest and thus can parse it without ignoring
+    // unknown values.
+    //
     void
-    serialize (butl::manifest_serializer&) const;
+    serialize (
+      butl::manifest_serializer&,
+      const butl::optional<butl::standard_version>& = butl::nullopt) const;
 
     // Serialize only package manifest header values.
     //
@@ -946,10 +957,12 @@ namespace bpkg
   // Serialize.
   //
   inline void
-  pkg_package_manifest (butl::manifest_serializer& s,
-                        const package_manifest& m)
+  pkg_package_manifest (
+    butl::manifest_serializer& s,
+    const package_manifest& m,
+    const butl::optional<butl::standard_version>& min_ver = butl::nullopt)
   {
-    m.serialize (s);
+    m.serialize (s, min_ver);
   }
 
   // Normally there is no need to serialize dir and git package manifests,
@@ -978,8 +991,14 @@ namespace bpkg
     pkg_package_manifests (butl::manifest_parser&,
                            bool ignore_unknown = false);
 
+    // If the minimum libbpkg version is specified, then also apply the
+    // required backward compatibility workarounds to the serialized package
+    // manifests list (see package_manifest::serialize() for details).
+    //
     void
-    serialize (butl::manifest_serializer&) const;
+    serialize (
+      butl::manifest_serializer&,
+      const butl::optional<butl::standard_version>& = butl::nullopt) const;
   };
 
   class LIBBPKG_EXPORT dir_package_manifests:
-- 
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