From f5afcb9205ef02adbea9f080ef6d39094e3e28d3 Mon Sep 17 00:00:00 2001
From: Olivier 'reivilibre <olivier@librepush.net>
Date: Tue, 15 Jun 2021 14:49:55 +0100
Subject: [PATCH] Merge UID and GID tables when integrating

---
 yama/src/commands.rs | 24 ++++++++++++++++++++----
 yama/src/tree.rs     | 26 ++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/yama/src/commands.rs b/yama/src/commands.rs
index 339aa2e..fe485fc 100644
--- a/yama/src/commands.rs
+++ b/yama/src/commands.rs
@@ -6,6 +6,7 @@ use std::sync::Arc;
 
 use anyhow::{anyhow, bail, Context};
 use clap::crate_version;
+use log::warn;
 
 use crate::chunking::{RecursiveChunker, RecursiveUnchunker, SENSIBLE_THRESHOLD};
 use crate::definitions::{PointerData, RecursiveChunkRef, RootTreeNode, TreeNode};
@@ -14,7 +15,7 @@ use crate::pile::integrity::RawPileIntegrityChecker;
 use crate::pile::local_sled::LocalSledRawPile;
 use crate::pile::local_sqlitebloblogs::SqliteBloblogPile;
 use crate::pile::{Pile, PileDescriptor, PileStorage, RawPile};
-use crate::tree::integrate_node_in_place;
+use crate::tree::{integrate_node_in_place, merge_uid_or_gid_tables};
 
 pub fn init(dir: &Path) -> anyhow::Result<()> {
     let yama_toml = dir.join("yama.toml");
@@ -142,14 +143,29 @@ pub fn fully_integrate_pointer_node<RP: RawPile>(
     tree_node: &mut TreeNode,
     pointer: &mut PointerData,
 ) -> anyhow::Result<()> {
-    if let Some(parent) = &pointer.parent_pointer {
+    if let Some(parent_name) = &pointer.parent_pointer {
         let mut parent = pile
-            .read_pointer(parent.as_str())?
-            .ok_or_else(|| anyhow!("Parent pointer {:?} not found.", parent))?;
+            .read_pointer(parent_name.as_str())?
+            .ok_or_else(|| anyhow!("Parent pointer {:?} not found.", parent_name))?;
         let mut parent_node = retrieve_tree_node(pile, parent.chunk_ref.clone())?.node;
 
         fully_integrate_pointer_node(pile, &mut parent_node, &mut parent)?;
         integrate_node_in_place(tree_node, &mut parent_node)?;
+
+        // merge in the UID and GID tables when integrating.
+        if merge_uid_or_gid_tables(&mut pointer.uid_lookup, &parent.uid_lookup) {
+            warn!(
+                "Overlap when merging parent:{:?}'s UID table into child.",
+                parent_name
+            );
+        }
+        if merge_uid_or_gid_tables(&mut pointer.gid_lookup, &parent.gid_lookup) {
+            warn!(
+                "Overlap when merging parent:{:?}'s GID table into child.",
+                parent_name
+            );
+        }
+
         pointer.parent_pointer = None;
     }
     Ok(())
diff --git a/yama/src/tree.rs b/yama/src/tree.rs
index 4432e54..8d2a60c 100644
--- a/yama/src/tree.rs
+++ b/yama/src/tree.rs
@@ -299,6 +299,32 @@ pub fn create_uidgid_lookup_tables(
     Ok(())
 }
 
+#[must_use]
+/// Accepts a target UID/GID map and a source UID/GID map.
+/// Merges source into target.
+/// Returns true if everything is OK, false if there is a warning (overlap!).
+/// In the event of an overlap, the pre-existing entry wins.
+pub fn merge_uid_or_gid_tables(
+    target: &mut BTreeMap<u16, Option<String>>,
+    source: &BTreeMap<u16, Option<String>>,
+) -> bool {
+    let mut warn = false;
+    for (uid_or_gid, name) in source.iter() {
+        match target.entry(*uid_or_gid) {
+            Entry::Vacant(entry) => {
+                entry.insert(name.clone());
+            }
+            Entry::Occupied(entry) => {
+                if entry.get() != name {
+                    // Conflicting IDs
+                    warn = true;
+                }
+            }
+        }
+    }
+    !warn
+}
+
 #[cfg(test)]
 mod tests {
     use crate::definitions::{