From 6ec744e7883f0314466f7eee7226726a096e9501 Mon Sep 17 00:00:00 2001
From: Yishuai Li <yishuai@upenn.edu>
Date: Tue, 14 Sep 2021 14:33:27 -0400
Subject: [PATCH] Allow empty patch version

---
 src/cppo_main.ml  | 8 ++++----
 test/dune         | 2 +-
 test/version.cppo | 2 ++
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/cppo_main.ml b/src/cppo_main.ml
index 93dd647..98e9efb 100644
--- a/src/cppo_main.ml
+++ b/src/cppo_main.ml
@@ -17,7 +17,7 @@ let add_extension tbl s =
 let semver_re = Str.regexp "\
 \\([0-9]+\\)\
 \\.\\([0-9]+\\)\
-\\.\\([0-9]+\\)\
+\\(\\.\\([0-9]+\\)\\)?\
 \\([~-]\\([^+]*\\)\\)?\
 \\(\\+\\(.*\\)\\)?\
 \r?$"
@@ -28,9 +28,9 @@ let parse_semver s =
   else
     let major = Str.matched_group 1 s in
     let minor = Str.matched_group 2 s in
-    let patch = Str.matched_group 3 s in
-    let prerelease = try Some (Str.matched_group 5 s) with Not_found -> None in
-    let build = try Some (Str.matched_group 7 s) with Not_found -> None in
+    let patch = try (Str.matched_group 4 s) with Not_found -> "0" in
+    let prerelease = try Some (Str.matched_group 6 s) with Not_found -> None in
+    let build = try Some (Str.matched_group 8 s) with Not_found -> None in
     Some (major, minor, patch, prerelease, build)
 
 let define var s =
diff --git a/test/dune b/test/dune
index a7fab7b..254e534 100644
--- a/test/dune
+++ b/test/dune
@@ -70,7 +70,7 @@
  (action
   (with-stdout-to
    %{targets}
-   (run %{bin:cppo} -V X:123.05.2-alpha.1+foo-2.1 %{<}))))
+   (run %{bin:cppo} -V X:123.05.2-alpha.1+foo-2.1 -V COQ:8.13+beta1 %{<}))))
 
 (alias
  (name runtest)
diff --git a/test/version.cppo b/test/version.cppo
index ee4e429..4b13350 100644
--- a/test/version.cppo
+++ b/test/version.cppo
@@ -28,3 +28,5 @@ patch: X_PATCH
 #else
   #error ""
 #endif
+
+Coq: COQ_VERSION