publish: print on failure, simplify logic

Should help with cases like #3397

The existing tests in tests/publishing/test_uploader.py should verify
that this doesn't cause regressions.

poetry/publishing/uploader.py

@@ -207,39 +207,19 @@ def post_data(self, file: Path) -> Dict[str, Any]:
 
     def _upload(
         self, session: requests.Session, url: str, dry_run: Optional[bool] = False
-    ) -> None:
-        try:
-            self._do_upload(session, url, dry_run)
-        except HTTPError as e:
-            if (
-                e.response.status_code == 400
-                and "was ever registered" in e.response.text
-            ):
-                try:
-                    self._register(session, url)
-                except HTTPError as e:
-                    raise UploadError(e)
-
-            raise UploadError(e)
-
-    def _do_upload(
-        self, session: requests.Session, url: str, dry_run: Optional[bool] = False
     ) -> None:
         for file in self.files:
             # TODO: Check existence
 
-            resp = self._upload_file(session, url, file, dry_run)
-
-            if not dry_run:
-                resp.raise_for_status()
+            self._upload_file(session, url, file, dry_run)
 
     def _upload_file(
         self,
         session: requests.Session,
         url: str,
         file: Path,
         dry_run: Optional[bool] = False,
-    ) -> requests.Response:
+    ) -> None:
         from cleo.ui.progress_bar import ProgressBar
 
         data = self.post_data(file)
@@ -290,6 +270,11 @@ def _upload_file(
                         "Redirects are not supported. "
                         "Is the URL missing a trailing slash?"
                     )
+                elif resp.status_code == 400 and "was ever registered" in resp.text:
+                    self._register(session, url)
+                    resp.raise_for_status()
+                else:
+                    resp.raise_for_status()
             except (requests.ConnectionError, requests.HTTPError) as e:
                 if self._io.output.is_decorated():
                     self._io.overwrite(
@@ -299,8 +284,6 @@ def _upload_file(
             finally:
                 self._io.write_line("")
 
-        return resp
-
     def _register(self, session: requests.Session, url: str) -> requests.Response:
         """
         Register a package to a repository.