From 0013236e5db378c68d72dedeaf0594e6a851cdd0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <clement@meilisearch.com>
Date: Mon, 28 Jun 2021 16:19:02 +0200
Subject: [PATCH] Fix the LMDB and heed invalid interactions.

It is undefined behavior to keep a reference to the database while
modifying it, we were keeping references in the database and also
feeding the heed put_current methods with keys referenced inside
the database itself.

https://github.com/Kerollmops/heed/pull/108
---
 milli/src/update/delete_documents.rs | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/milli/src/update/delete_documents.rs b/milli/src/update/delete_documents.rs
index e291eb106..30ae55e62 100644
--- a/milli/src/update/delete_documents.rs
+++ b/milli/src/update/delete_documents.rs
@@ -197,7 +197,8 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
                         iter.del_current()?;
                         *must_remove = true;
                     } else if docids.len() != previous_len {
-                        iter.put_current(key, &docids)?;
+                        let key = key.to_owned();
+                        iter.put_current(&key, &docids)?;
                     }
                 }
             }
@@ -238,13 +239,14 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
         let mut iter = word_prefix_docids.iter_mut(self.wtxn)?;
         while let Some(result) = iter.next() {
             let (prefix, mut docids) = result?;
+            let prefix = prefix.to_owned();
             let previous_len = docids.len();
             docids.difference_with(&self.documents_ids);
             if docids.is_empty() {
                 iter.del_current()?;
                 prefixes_to_delete.insert(prefix)?;
             } else if docids.len() != previous_len {
-                iter.put_current(prefix, &docids)?;
+                iter.put_current(&prefix, &docids)?;
             }
         }
 
@@ -281,7 +283,8 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
             if docids.is_empty() {
                 iter.del_current()?;
             } else if docids.len() != previous_len {
-                iter.put_current(key, &docids)?;
+                let key = key.to_owned();
+                iter.put_current(&key, &docids)?;
             }
         }
 
@@ -299,7 +302,8 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
             if docids.is_empty() {
                 iter.del_current()?;
             } else if docids.len() != previous_len {
-                iter.put_current(bytes, &docids)?;
+                let bytes = bytes.to_owned();
+                iter.put_current(&bytes, &docids)?;
             }
         }
 
@@ -315,7 +319,8 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
             if docids.is_empty() {
                 iter.del_current()?;
             } else if docids.len() != previous_len {
-                iter.put_current(bytes, &docids)?;
+                let bytes = bytes.to_owned();
+                iter.put_current(&bytes, &docids)?;
             }
         }
 
@@ -331,7 +336,8 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
             if docids.is_empty() {
                 iter.del_current()?;
             } else if docids.len() != previous_len {
-                iter.put_current(bytes, &docids)?;
+                let bytes = bytes.to_owned();
+                iter.put_current(&bytes, &docids)?;
             }
         }
 
@@ -437,7 +443,8 @@ where
         if docids.is_empty() {
             iter.del_current()?;
         } else if docids.len() != previous_len {
-            iter.put_current(bytes, &docids)?;
+            let bytes = bytes.to_owned();
+            iter.put_current(&bytes, &docids)?;
         }
     }