Fix duplicated version tags in egg_info

Previously egg_info was adding duplicated tags to the version string.
This was happening because of the version normalization.
When the version normalization was applied to the string the tag was
modified, then later egg_info could no longer recognize it before
applying.

The fix for this problem was to normalize the tag string before
applying.

1 files changed, 7 insertions, 2 deletions

diff --git a/setuptools/command/egg_info.py b/setuptools/command/egg_info.py
index 63389654..ea47e519 100644
--- a/setuptools/command/egg_info.py
+++ b/setuptools/command/egg_info.py
@@ -140,13 +140,18 @@ class InfoCommon:
             else version + self.vtags
         )
 
-    def tags(self):
+    def _safe_tags(self, tags: str) -> str:
+        # To implement this we can rely on `safe_version` pretending to be version 0
+        # followed by tags. Then we simply discard the starting 0 (fake version number)
+        return safe_version(f"0{tags}")[1:]
+
+    def tags(self) -> str:
         version = ''
         if self.tag_build:
             version += self.tag_build
         if self.tag_date:
             version += time.strftime("-%Y%m%d")
-        return version
+        return self._safe_tags(version)
     vtags = property(tags)