fix(cross-repo): stop a "::missed" shadow row making a project unresolvable

Indexing writes an internal "<name>::missed" miss-graph row into the SAME db as
the primary project whenever a file parses partially. cr_store_has_exact_project
required `count == 1` over ALL rows returned by cbm_store_list_projects, which
does not filter those rows - so any project that had ever recorded a parse miss
failed validation, as SOURCE and as TARGET, and the whole feature reported:

    project is not indexed

for a project that plainly was. There is no user-level workaround: a partial
parse is not something the operator controls, and re-indexing reproduces the
shadow row.

This is the same defect mcp.c fixed for list_projects in #1044 ("requiring
n == 1 over ALL rows made every project with a miss graph vanish"); the
cross-repo site never learned it. The fix ports that primary-row filter.

The single-primary requirement itself is deliberately kept: it is what proves
the db belongs to the project we were asked about rather than being a shared or
mislabelled store. Only "::" shadow rows stop counting toward it.

Reported by vitaliy-shatskiy in #1609, whose diagnosis named the exact function
and the exact reason.

Reproduce-first, and revert-checked both ways:
  - the new test fails on origin/main with `ASSERT(!(result.failed))`
    (tests/test_cross_repo.c), for the behaviour under test rather than a setup
    error;
  - it passes with the fix;
  - reverting ONLY src/pipeline/pass_cross_repo.c and keeping the test brings
    the identical RED back, so the test binds to the production change.

The existing pair without shadow rows is the control: those tests already prove
that path returns edges, so this cannot pass vacuously on a fixture that never
matched.

cross_repo 8 passed; pipeline 249 passed; store_edges 25 and store_nodes 67
passed - no collateral change.

Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>

src/pipeline/pass_cross_repo.c

@@ -123,9 +123,32 @@ static int cr_project_compare(const void *left, const void *right) {
 static bool cr_store_has_exact_project(cbm_store_t *store, const char *project) {
     cbm_project_t *projects = NULL;
     int count = 0;
-    bool matches = store && cbm_store_check_integrity(store) &&
-                   cbm_store_list_projects(store, &projects, &count) == CBM_STORE_OK &&
-                   count == 1 && projects[0].name && strcmp(projects[0].name, project) == 0;
+    if (!store || !cbm_store_check_integrity(store) ||
+        cbm_store_list_projects(store, &projects, &count) != CBM_STORE_OK) {
+        cbm_store_free_projects(projects, count);
+        return false;
+    }
+    /* Ignore internal shadow projects ("<name>::missed" miss-graph rows): they
+     * live in the SAME db as the primary project, so any project that has ever
+     * recorded a parse miss carries two rows. Requiring count == 1 over ALL rows
+     * therefore made such a project unresolvable as source AND as target, and
+     * cross-repo reported it as not indexed when it plainly was (#1609). This is
+     * the same defect mcp.c fixed for list_projects in #1044; this site never
+     * learned it.
+     *
+     * The single-primary requirement itself is kept: it is what proves this db
+     * belongs to the project we were asked about, rather than being a shared or
+     * mislabelled store. Only the shadow rows stop counting toward it. */
+    int primary_count = 0;
+    bool primary_matches = false;
+    for (int i = 0; i < count; i++) {
+        const char *name = projects[i].name;
+        if (name && name[0] && !strstr(name, "::")) {
+            primary_count++;
+            primary_matches = strcmp(name, project) == 0;
+        }
+    }
+    bool matches = primary_count == 1 && primary_matches;
     cbm_store_free_projects(projects, count);
     return matches;
 }

tests/test_cross_repo.c

@@ -469,7 +469,58 @@ TEST(cross_repo_pre_cancel_preserves_existing_cross_edges) {
     PASS();
 }
 
+/* Add the internal "<name>::missed" miss-graph row that indexing writes into
+ * the SAME db whenever a file parses partially. */
+static bool cross_repo_add_missed_shadow(const cross_repo_fixture_t *fixture, const char *project) {
+    char path[512];
+    char shadow[256];
+    if (!cross_repo_project_path(fixture, project, path, sizeof(path))) {
+        return false;
+    }
+    snprintf(shadow, sizeof(shadow), "%s::missed", project);
+    cbm_store_t *store = cbm_store_open_path(path);
+    if (!store) {
+        return false;
+    }
+    bool ok = cbm_store_upsert_project(store, shadow, fixture->cache) == CBM_STORE_OK;
+    cbm_store_close(store);
+    return ok;
+}
+
+/* #1609: any project that has ever recorded a parse miss carries a
+ * "<name>::missed" shadow row in its own db. cr_store_has_exact_project
+ * demanded count == 1 over ALL rows, so that second row made the project
+ * unresolvable — as source AND as target — and the whole feature failed with
+ * "not indexed" for a project that plainly was. mcp.c already solved exactly
+ * this shape for list_projects in #1044; this site never learned it.
+ *
+ * The control is the pair without shadow rows: the tests above already prove
+ * that path returns edges, so a regression here cannot hide behind a fixture
+ * that never matched in the first place. */
+TEST(cross_repo_accepts_project_with_missed_shadow_row_issue1609) {
+    cross_repo_fixture_t fixture;
+    bool setup = cross_repo_fixture_begin(&fixture) &&
+                 cross_repo_seed_http_pair(&fixture, "shadow-source", "shadow-target", "/orders",
+                                           "s") &&
+                 cross_repo_add_missed_shadow(&fixture, "shadow-source") &&
+                 cross_repo_add_missed_shadow(&fixture, "shadow-target");
+    if (!setup) {
+        cross_repo_fixture_end(&fixture);
+        FAIL("failed to seed shadow-row fixture");
+    }
+
+    const char *target = "shadow-target";
+    cbm_cross_repo_result_t result = cbm_cross_repo_match("shadow-source", &target, 1);
+    cross_repo_fixture_end(&fixture);
+
+    ASSERT_FALSE(result.failed);
+    ASSERT_EQ(result.projects_scanned, 1);
+    ASSERT_EQ(result.http_edges, 1);
+    PASS();
+}
+
 SUITE(cross_repo) {
+    RUN_TEST(cross_repo_accepts_project_with_missed_shadow_row_issue1609);
     RUN_TEST(cross_repo_null_target_fails_without_dereference);
     RUN_TEST(cross_repo_wildcard_keeps_projects_containing_internal_tokens);
     RUN_TEST(cross_repo_scan_bound_counts_examined_rows_not_matches);