Default version epoch to one

3 files changed, 69 insertions, 29 deletions

diff --git a/libbpkg/manifest.cxx b/libbpkg/manifest.cxx
index f155c5a..0fa2a4c 100644
--- a/libbpkg/manifest.cxx
+++ b/libbpkg/manifest.cxx
@@ -238,8 +238,18 @@ namespace bpkg
     size_t len_ = 0; // Length without the trailing digit-only zero components.
   };
 
+  // Return zero for versions having the '0[+<revision>]' form (stubs) and one
+  // otherwise. Used for both version and version::data_type types.
+  //
+  template <typename T>
+  inline static uint16_t
+  default_epoch (const T& v)
+  {
+    return v.canonical_upstream.empty () && !v.release ? 0 : 1;
+  }
+
   version::data_type::
-  data_type (const char* v, parse pr): epoch (0), revision (0)
+  data_type (const char* v, parse pr): revision (0)
   {
     // Otherwise compiler gets confused with string() member.
     //
@@ -255,6 +265,8 @@ namespace bpkg
 
     assert (v != nullptr);
 
+    optional<uint16_t> ep;
+
     auto bad_arg = [](const string& d) {throw invalid_argument (d);};
 
     auto uint16 = [&bad_arg](const string& s, const char* what) -> uint16_t
@@ -331,7 +343,7 @@ namespace bpkg
             if (lnn >= cb) // Contains non-digits.
               bad_arg ("epoch should be 2-byte unsigned integer");
 
-            epoch = uint16 (string (cb, p), "epoch");
+            ep = uint16 (string (cb, p), "epoch");
           }
           else
             canon_part->add (cb, p, lnn < cb);
@@ -467,11 +479,17 @@ namespace bpkg
       }
     }
 
-    if (pr == parse::full && epoch == 0 && canonical_upstream.empty () &&
-        canonical_release.empty ())
+    if (pr == parse::full)
     {
-      assert (revision == 0); // Can't happen if through all previous checks.
-      bad_arg ("empty version");
+      epoch = ep ? *ep : default_epoch (*this);
+
+      if (epoch == 0                  &&
+          canonical_upstream.empty () &&
+          canonical_release.empty ())
+      {
+        assert (revision == 0); // Can't happen if through all previous checks.
+        bad_arg ("empty version");
+      }
     }
   }
 
@@ -502,7 +520,7 @@ namespace bpkg
     if (empty ())
       throw logic_error ("empty version");
 
-    std::string v (epoch != 0
+    std::string v (epoch != default_epoch (*this)
                    ? '+' + to_string (epoch) + '-' + upstream
                    : upstream);
 
diff --git a/libbpkg/manifest.hxx b/libbpkg/manifest.hxx
index 5e7a748..fc6c332 100644
--- a/libbpkg/manifest.hxx
+++ b/libbpkg/manifest.hxx
@@ -50,7 +50,7 @@ namespace bpkg
     const std::string canonical_release;
 
     // Create a special empty version. It is less than any other valid
-    // version (and is conceptually equivalent to 0-).
+    // version (and is conceptually equivalent to +0-0-).
     //
     version (): epoch (0), release (""), revision (0), iteration (0) {}
 
diff --git a/tests/package-version/driver.cxx b/tests/package-version/driver.cxx
index 70ea892..5cdf4f9 100644
--- a/tests/package-version/driver.cxx
+++ b/tests/package-version/driver.cxx
@@ -114,8 +114,8 @@ namespace bpkg
       assert (bad_version ("a.b-+1"));        // Revision for empty release.
       assert (bad_version ("0.0-+3"));        // Same.
       assert (bad_version ("1.2.3-~"));       // Invalid release.
-      assert (bad_version ("0-"));            // Illegal version.
-      assert (bad_version ("0.0-"));          // Same.
+      assert (bad_version ("+0-0-"));         // Empty version.
+      assert (bad_version ("+0-0.0-"));       // Same.
       assert (bad_version ("1.2.3+1#1"));     // Unexpected iteration.
 
       assert (bad_version ("a.39485739122323231.3")); // Too long component.
@@ -151,7 +151,15 @@ namespace bpkg
       {
         version v ("+1-0.0-");
         assert (!v.empty ());
-        assert (v.string () == "+1-0.0-");
+        assert (v.string () == "0.0-");
+        assert (v.canonical_upstream.empty ());
+        assert (v.canonical_release.empty ());
+        assert (test_constructor (v));
+      }
+      {
+        version v ("0-");
+        assert (!v.empty ());
+        assert (v.string () == "0-");
         assert (v.canonical_upstream.empty ());
         assert (v.canonical_release.empty ());
         assert (test_constructor (v));
@@ -181,6 +189,12 @@ namespace bpkg
         assert (test_constructor (v));
       }
       {
+        version v ("0+1");
+        assert (v.string () == "0+1");
+        assert (v.canonical_upstream.empty ());
+        assert (test_constructor (v));
+      }
+      {
         version v ("0.0.0");
         assert (v.string () == "0.0.0");
         assert (v.canonical_upstream.empty ());
@@ -217,8 +231,14 @@ namespace bpkg
         assert (test_constructor (v));
       }
       {
+        version v ("+0-0+1");
+        assert (v.string () == "0+1");
+        assert (v.canonical_upstream.empty ());
+        assert (test_constructor (v));
+      }
+      {
         version v ("+0-A+1");
-        assert (v.string () == "A+1");
+        assert (v.string () == "+0-A+1");
         assert (v.canonical_upstream == "a");
         assert (test_constructor (v));
       }
@@ -258,7 +278,7 @@ namespace bpkg
       }
       {
         version v ("+1-A-1.2.3B.00+0");
-        assert (v.string () == "+1-A-1.2.3B.00");
+        assert (v.string () == "A-1.2.3B.00");
         assert (v.release && *v.release == "1.2.3B.00");
         assert (v.canonical_release == "0000000000000001.0000000000000002.3b");
         assert (test_constructor (v));
@@ -271,43 +291,46 @@ namespace bpkg
         assert (test_constructor (v));
       }
       {
-        version v (1, "1", nullopt, 2, 0);
-        assert (v.string () == "+1-1+2");
+        version v (2, "1", nullopt, 2, 0);
+        assert (v.string () == "+2-1+2");
         assert (!v.release);
         assert (v.canonical_release == "~");
         assert (test_constructor (v));
       }
       {
-        version v (1, "1", string (), 0, 0);
-        assert (v.string () == "+1-1-");
+        version v (2, "1", string (), 0, 0);
+        assert (v.string () == "+2-1-");
         assert (v.release && v.release->empty ());
         assert (v.canonical_release.empty ());
         assert (test_constructor (v));
       }
       {
-        version v (1, "2.0", nullopt, 3, 4);
-        assert (v.string (false, false) == "+1-2.0+3#4");
-        assert (v.string (true,  true)  == "+1-2.0");
-        assert (v.string (true,  false) == "+1-2.0");
-        assert (v.string (false, true)  == "+1-2.0+3");
+        version v (3, "2.0", nullopt, 3, 4);
+        assert (v.string (false, false) == "+3-2.0+3#4");
+        assert (v.string (true,  true)  == "+3-2.0");
+        assert (v.string (true,  false) == "+3-2.0");
+        assert (v.string (false, true)  == "+3-2.0+3");
 
-        assert (version (1, "2.0", nullopt, 0, 3).string () == "+1-2.0#3");
-        assert (version (1, "2.0", nullopt, 3, 0).string () == "+1-2.0+3");
+        assert (version (3, "2.0", nullopt, 0, 1).string () == "+3-2.0#1");
+        assert (version (3, "2.0", nullopt, 1, 0).string () == "+3-2.0+1");
       }
 
+      assert (version ("+1-0-") == version ("0-")); // Not a stub.
+      assert (version ("00+1") == version ("0+1")); // Stub.
+      assert (version ("0.0.0") == version ("0"));  // Stub.
       assert (version ("a") == version ("a"));
       assert (version ("a") < version ("b"));
       assert (version ("a") < version ("aa"));
       assert (version ("a.a") < version ("aaa"));
       assert (version ("a") < version ("a.a"));
-      assert (version ("ab") == version ("ab"));
+      assert (version ("+1-ab") == version ("ab"));
       assert (version ("ac") < version ("bc"));
       assert (version ("ab+0") == version ("ab"));
       assert (version ("a.1+1") > version ("a.1"));
-      assert (version ("+0-ab") == version ("ab"));
+      assert (version ("ab") == version ("ab"));
       assert (version ("1.2") > version ("1.1"));
-      assert (version ("+1-1.0") > version ("2.0"));
-      assert (version ("+0-ab+1") == version ("ab+1"));
+      assert (version ("1.0") > version ("+0-2.0"));
+      assert (version ("+1-ab+1") == version ("ab+1"));
       assert (version ("+0-ab+1").compare (version ("+0-ab+2"), true) == 0);
       assert (version ("12") > version ("2"));
       assert (version ("2") < version ("12"));
@@ -322,7 +345,6 @@ namespace bpkg
       assert (version ("1.Alpha.1") == version ("1.ALPHA.1"));
       assert (version ("a.1") < version ("ab1"));
       assert (version ("a.2") < version ("a.1b"));
-      assert (version ("0.0.0") == version ("0"));
       assert (version ("1.0.0") == version ("01"));
       assert (version ("0.1.00") == version ("00.1"));
       assert (version ("0.0a.00") == version ("00.0a"));