Change firstGeq to compare to param1

Facade.h

@@ -30,6 +30,8 @@ struct Facade {
       facade->versioned.firstGeq(key, v, versionedIter, 2);
 
       if (versionedIter[0] == versionedIter[1]) {
+        // No mutations intersect [begin, end)
+        facade->unversionedRead(begin, end, limit, reverse, result);
         return result;
       }
 
@@ -40,9 +42,10 @@ struct Facade {
         weaselab::VersionedMap::Iterator iter = versionedIter[1];
         weaselab::VersionedMap::Iterator endIter = versionedIter[0];
         String readUntil = end;
-        if (iter == facade->versioned.end(version)) {
-          --iter;
-        }
+
+        // Make *iter intersect [begin, end)
+        --iter;
+
         for (;; --iter) {
           auto m = *iter;
           const auto mEnd =

FacadeTest.cpp

@@ -47,7 +47,7 @@ int main() {
   for (int64_t i = 1; i < version; ++i) {
     printf("--- version %" PRId64 " ---\n", i);
     printf("merged:\n");
-    auto result = f.viewAt(i).rangeRead("a"_s, "z"_s, 100, false);
+    auto result = f.viewAt(i).rangeRead("a"_s, "e"_s, 100, false);
     for (const auto &[k, v] : result) {
       for (auto c : k) {
         if (isprint(c)) {

VersionedMap.cpp

@@ -390,6 +390,17 @@ auto operator<=>(const VersionedMap::Key &lhs, const Node &rhs) {
   return lhs.len <=> rhs.entry->keyLen;
 }
 
+auto operator<=>(const VersionedMap::Key &lhs, const VersionedMap::Key &rhs) {
+  int cl = std::min(lhs.len, rhs.len);
+  if (cl > 0) {
+    int c = memcmp(lhs.p, rhs.p, cl);
+    if (c != 0) {
+      return c <=> 0;
+    }
+  }
+  return lhs.len <=> rhs.len;
+}
+
 constexpr int orderToInt(std::strong_ordering o) {
   return o == std::strong_ordering::less    ? -1
          : o == std::strong_ordering::equal ? 0
@@ -1156,6 +1167,11 @@ void VersionedMap::Impl::firstGeq(const Key *key, const int64_t *version,
     } else {
       iterator[i].impl->mutationIndex = 0;
     }
+
+    auto m = *iterator[i];
+    if (Key{m.param1, m.param1Len} < key[i]) {
+      ++iterator[i];
+    }
   }
 }
 

include/VersionedMap.h

@@ -150,11 +150,9 @@ struct __attribute__((__visibility__("default"))) VersionedMap {
     Impl *impl = nullptr;
   };
 
-  /** Perform `count` "first greater than or equal to" queries. If there's a
-   * mutation intersecting `key[i]` at `version[i]` then `iterator[i]` will
-   * point to that mutation. Otherwise it points to the first mutation greater
-   * or `end()` if none exists.  `version[i]` must be >= `getOldestVersion()`
-   * and <= `getVersion()`.
+  /** Perform `count` "first greater than or equal to" queries, comparing to
+   * mutations' `param1`. `version[i]` must be >= `getOldestVersion()` and <=
+   * `getVersion()`.
    *
    * Thread-safe as long as a version is not concurrently invalidated by
    * `setOldestVersion`. There's a performance benefit if you pass iterator[i]