Fix a bug where updating the workspace could remove uncommitted changes

Author: krlvi

crates/gitbutler-branch-actions/src/upstream_integration.rs

@@ -503,8 +503,6 @@ pub(crate) fn integrate_upstream(
                 continue;
             };
 
-            stack.set_stack_head(command_context, *head, Some(*tree))?;
-
             // Update the branch heads
             if let Some(output) = rebase_output {
                 let mut new_heads: HashMap<String, git2::Commit<'_>> = HashMap::new();
@@ -516,6 +514,7 @@ pub(crate) fn integrate_upstream(
                 }
                 stack.set_all_heads(command_context, new_heads)?;
             }
+            stack.set_stack_head(command_context, *head, Some(*tree))?;
 
             let mut archived_branches =
                 stack.archive_integrated_heads(command_context, for_archival)?;

crates/gitbutler-stack/src/stack.rs

@@ -695,12 +695,9 @@ impl Stack {
         {
             return Err(anyhow!("The new head names do not match the current heads"));
         }
-        let stack_head = self.head();
         let gix_repo = ctx.gix_repository()?;
         for head in &mut self.heads {
             if let Some(commit) = new_heads.get(head.name()) {
-                let new_head = commit.clone().into();
-                validate_target(&new_head, ctx.repo(), stack_head, &state)?;
                 head.set_head(commit.clone().into(), &gix_repo)?;
             }
         }