lib: mild refactoring made possible by previous commit

Inline `create_descendant_commits`, move some functionality of
`DescendantRebaser::rebase_next` to `rebase_all`, a seemingly more logical
location.

lib/src/repo.rs

@@ -861,21 +861,6 @@ impl MutableRepo {
         !(self.rewritten_commits.is_empty() && self.abandoned_commits.is_empty())
     }
 
-    /// Creates a `DescendantRebaser` to rebase descendants of the recorded
-    /// rewritten and abandoned commits.
-    // TODO(ilyagr): Inline this. It's only used in tests.
-    fn create_descendant_rebaser<'settings, 'repo>(
-        &'repo mut self,
-        settings: &'settings UserSettings,
-    ) -> DescendantRebaser<'settings, 'repo> {
-        DescendantRebaser::new(
-            settings,
-            self,
-            self.rewritten_commits.clone(),
-            self.abandoned_commits.clone(),
-        )
-    }
-
     fn rebase_descendants_return_rebaser<'settings, 'repo>(
         &'repo mut self,
         settings: &'settings UserSettings,
@@ -885,7 +870,12 @@ impl MutableRepo {
             // Optimization
             return Ok(None);
         }
-        let mut rebaser = self.create_descendant_rebaser(settings);
+        let mut rebaser = DescendantRebaser::new(
+            settings,
+            self,
+            self.rewritten_commits.clone(),
+            self.abandoned_commits.clone(),
+        );
         *rebaser.mut_options() = options;
         rebaser.rebase_all()?;
         Ok(Some(rebaser))

lib/src/rewrite.rs

@@ -587,6 +587,11 @@ impl<'settings, 'repo> DescendantRebaser<'settings, 'repo> {
                 new_commit,
             }));
         }
+        Ok(None)
+    }
+
+    pub fn rebase_all(&mut self) -> Result<(), TreeMergeError> {
+        while self.rebase_next()?.is_some() {}
         // TODO: As the TODO above says, we should probably change the API. Even if we
         // don't, we should at least make this code not do any work if you call
         // rebase_next() after we've returned None.
@@ -600,11 +605,6 @@ impl<'settings, 'repo> DescendantRebaser<'settings, 'repo> {
         self.heads_to_remove.clear();
         self.heads_to_add.clear();
         self.mut_repo.set_view(view);
-        Ok(None)
-    }
-
-    pub fn rebase_all(&mut self) -> Result<(), TreeMergeError> {
-        while self.rebase_next()?.is_some() {}
         Ok(())
     }
 }