Fix `history_manager.search(?, unique=True)` returning old entries

IPython/core/history.py

@@ -265,7 +265,7 b' class HistoryAccessor(HistoryAccessorBase):'
     ## -------------------------------
     ## Methods for retrieving history:
     ## -------------------------------
-    def _run_sql(self, sql, params, raw=True, output=False):
+    def _run_sql(self, sql, params, raw=True, output=False, latest=False):
         """Prepares and runs an SQL query for the history database.
 
         Parameters
@@ -276,6 +276,8 b' class HistoryAccessor(HistoryAccessorBase):'
           Parameters passed to the SQL query (to replace "?")
         raw, output : bool
           See :meth:`get_range`
+        latest : bool
+          Select rows with max (session, line)
 
         Returns
         -------
@@ -286,8 +288,12 b' class HistoryAccessor(HistoryAccessorBase):'
         if output:
             sqlfrom = "history LEFT JOIN output_history USING (session, line)"
             toget = "history.%s, output_history.output" % toget
+        if latest:
+            toget += ", MAX(session * 128 * 1024 + line)"
         cur = self.db.execute("SELECT session, line, %s FROM %s " %\
                                 (toget, sqlfrom) + sql, params)
+        if latest:
+            cur = (row[:-1] for row in cur)
         if output:    # Regroup into 3-tuples, and parse JSON
             return ((ses, lin, (inp, out)) for ses, lin, inp, out in cur)
         return cur
@@ -395,7 +401,7 b' class HistoryAccessor(HistoryAccessorBase):'
             params += (n,)
         elif unique:
             sqlform += " ORDER BY session, line"
-        cur = self._run_sql(sqlform, params, raw=raw, output=output)
+        cur = self._run_sql(sqlform, params, raw=raw, output=output, latest=unique)
         if n is not None:
             return reversed(list(cur))
         return cur
@@ -817,7 +823,7 b' class HistorySavingThread(threading.Thread):'
         try:
             self.db = sqlite3.connect(
                 str(self.history_manager.hist_file),
-                **self.history_manager.connection_options
+                **self.history_manager.connection_options,
             )
             while True:
                 self.history_manager.save_flag.wait()

IPython/core/tests/test_history.py

@@ -17,12 +17,10 b' import sqlite3'
 from traitlets.config.loader import Config
 from IPython.utils.tempdir import TemporaryDirectory
 from IPython.core.history import HistoryManager, extract_hist_ranges
-from IPython.testing.decorators import skipif
 
 def test_proper_default_encoding():
     assert sys.getdefaultencoding() == "utf-8"
 
-@skipif(sqlite3.sqlite_version_info > (3,24,0))
 def test_history():
     ip = get_ipython()
     with TemporaryDirectory() as tmpdir:
@@ -133,6 +131,17 b' def test_history():'
             ip.history_manager.store_inputs(1, "rogue")
             ip.history_manager.writeout_cache()
             assert ip.history_manager.session_number == 3
+
+            # Check that session and line values are not just max values
+            sessid, lineno, entry = newhist[-1]
+            assert lineno > 1
+            ip.history_manager.reset()
+            lineno = 1
+            ip.history_manager.store_inputs(lineno, entry)
+            gothist = ip.history_manager.search("*=*", unique=True)
+            hist = list(gothist)[-1]
+            assert sessid < hist[0]
+            assert hist[1:] == (lineno, entry)
         finally:
             # Ensure saving thread is shut down before we try to clean up the files
             ip.history_manager.save_thread.stop()