[move-package] Support dependency overrides

language/tools/move-package/src/resolution/dependency_graph.rs

@@ -968,6 +968,11 @@ impl DependencyGraph {
     ) -> Result<Option<Package>> {
         match self.package_table.entry(name) {
             Entry::Vacant(entry) => {
+                // Note that we simply insert a dependent package here without checking the
+                // overrides set. The reason for it is that if there was an override for this entry,
+                // it would have already been inserted as the overrides are processed before
+                // non-overridden dependencies (and only after they are processed, the overrides set
+                // is populated).
                 entry.insert(pkg.clone());
                 Ok(None)
             }

language/tools/move-package/tests/test_sources/diamond_problem_dep_incorrect_override_cycle/Move.toml

@@ -1,4 +1,4 @@
-# Dependency graph and and override (ov) - when override is processed there is no entry in the graph
+# Dependency graph and override (ov) - when override is processed there is no entry in the graph
 # yet (override is incorrect). This part is the same as in the
 # diamond_problem_dep_incorrect_override_empty test. Additionally, a cycle introduced during graph
 # construction interferes with part of the algorithm responsible for validating potentially

language/tools/move-package/tests/test_sources/diamond_problem_dep_nested_conflict/Move.toml

@@ -12,9 +12,9 @@
 # |Root|----+                          +---->| E  |------+       |
 # +----+    |                                +----+      |       |
 #           |                                        v1  |       |
-#           |     +----+     +---+    v3     +----+<-----+       |
-#           +---->| B  +---->| D |---------->| G  |  v2          |
-#                 +----+     +---+           +----+<-------------+
+#           |     +----+     +----+    v3    +----+<-----+       |
+#           +---->| B  +---->| D  |--------->| G  |  v2          |
+#                 +----+     +----+          +----+<-------------+
 [package]
 name = "Root"
 version = "0.0.0"