fix: StGit-specific branch config handling

When renaming, deleting, or cleaning-up branches, the branch and StGit
specific configuration section, i.e. "branch.<branch>.stgit" was not being
handled correctly.

For `stg branch --rename`, this config section was not being renamed along
with the branch.

For `stg branch --delete` and `stg branch --cleanup`, this section was not
being entirely removed; the section heading would remain, but with no
values.

Author: jpgrayson

src/cmd/branch.rs

@@ -573,8 +573,14 @@ fn rename(repo: &git2::Repository, matches: &ArgMatches) -> Result<()> {
             false,
             &format!("rename {old_branchname} to {new_branchname}"),
         )?;
-        stack.deinitialize()?;
+        stupid
+            .config_rename_section(
+                &format!("branch.{old_branchname}.stgit"),
+                &format!("branch.{new_branchname}.stgit"),
+            )
+            .ok();
         stupid.branch_move(Some(old_branchname), new_branchname)?;
+        stack.deinitialize()?;
     } else {
         stupid.branch_move(Some(old_branchname), new_branchname)?;
     }

src/stack/stack.rs

@@ -10,7 +10,7 @@ use super::{
     state::StackState, transaction::TransactionBuilder, upgrade::stack_upgrade, PatchState,
     StackStateAccess,
 };
-use crate::{patchname::PatchName, repo::RepositoryExtended};
+use crate::{patchname::PatchName, repo::RepositoryExtended, stupid::Stupid};
 
 /// StGit stack
 ///
@@ -75,29 +75,19 @@ impl<'repo> Stack<'repo> {
             refname,
             ..
         } = self;
-        let mut config = repo.config()?;
         let mut state_ref = repo.find_reference(&refname)?;
         let patch_ref_glob = get_patch_refname(&branch_name, "*");
         for patch_reference in repo.references_glob(&patch_ref_glob)? {
             let mut patch_reference = patch_reference?;
             patch_reference.delete()?;
         }
         state_ref.delete()?;
-        let mut config_to_delete: Vec<_> = Vec::new();
-
-        {
-            let mut entries = config.entries(Some(&format!("branch.{branch_name}.stgit")))?;
-            while let Some(entry) = entries.next() {
-                let entry = entry?;
-                if let Some(name) = entry.name() {
-                    config_to_delete.push(name.to_string());
-                }
-            }
-        }
 
-        for name_to_delete in config_to_delete {
-            config.remove(&name_to_delete)?;
-        }
+        // It is ok if the StGit-specific config section does not exist.
+        repo.stupid()
+            .config_remove_section(&format!("branch.{branch_name}.stgit"))
+            .ok();
+
         Ok(())
     }
 

src/stupid/mod.rs

@@ -420,6 +420,26 @@ impl<'repo, 'index> StupidContext<'repo, 'index> {
         parse_oid(&output.stdout)
     }
 
+    pub(crate) fn config_remove_section(&self, section_name: &str) -> Result<()> {
+        self.git()
+            .args(["config", "--local", "--remove-section"])
+            .arg(section_name)
+            .stdout(Stdio::null())
+            .output_git()?
+            .require_success("config --remove-section")?;
+        Ok(())
+    }
+
+    pub(crate) fn config_rename_section(&self, old_name: &str, new_name: &str) -> Result<()> {
+        self.git()
+            .args(["config", "--local", "--rename-section"])
+            .args([old_name, new_name])
+            .stdout(Stdio::null())
+            .output_git()?
+            .require_success("config --rename-section")?;
+        Ok(())
+    }
+
     /// Interactive diff
     pub(crate) fn diff<SpecIter, SpecArg, OptIter, OptArg>(
         &self,