Fixed inconsistencies generated by _md_shrink. (#1229)

Romain-Geissler-1A · web-flow · commit ac621054343a · 2025-06-30T15:02:55.000+02:00
This is causing assertion failures in ASSERT_CONSISTENT if an entry used to have a non null identity. Since the new entries will be concentrated at the beginning of the array, we shall "erase" the old entries that are at the end of the array and that won't be used anymore. This is enough to fix the core dump issues found in the testsuite of httpie in Fedora Rawhide (see #1195 (comment))
diff --git a/CHANGES/1229.bugfix.rst b/CHANGES/1229.bugfix.rst
@@ -0,0 +1 @@
+Fixed inconsistencies generated by the C implementation of ``_md_shrink()`` which might later lead to assertion failures and crash -- by :user:`Romain-Geissler-1A`.
diff --git a/multidict/_multilib/hashtable.h b/multidict/_multilib/hashtable.h
@@ -261,6 +261,7 @@ _md_shrink(MultiDictObject *md, bool update)
     keys->nentries = newnentries;
     keys->usable += nentries - newnentries;
     memset(&keys->indices[0], 0xff, ((size_t)1 << keys->log2_index_bytes));
+    memset(new_ep, 0, sizeof(entry_t) * (size_t)(nentries - newnentries));
     if (htkeys_build_indices(keys, entries, newnentries, update) < 0) {
         return -1;
     }

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Fixed inconsistencies generated by the C implementation of ``_md_shrink()`` which might later lead to assertion failures and crash -- by :user:`Romain-Geissler-1A`.
Original file line number	Diff line number	Diff line change
`@@ -261,6 +261,7 @@ _md_shrink(MultiDictObject *md, bool update)`
`261`	`261`	`keys->nentries = newnentries;`
`262`	`262`	`keys->usable += nentries - newnentries;`
`263`	`263`	`memset(&keys->indices[0], 0xff, ((size_t)1 << keys->log2_index_bytes));`
	`264`	`+ memset(new_ep, 0, sizeof(entry_t) * (size_t)(nentries - newnentries));`
`264`	`265`	`if (htkeys_build_indices(keys, entries, newnentries, update) < 0) {`
`265`	`266`	`return -1;`
`266`	`267`	`}`