8261692: Bugs in clhsdb history support

Reviewed-by: amenkov, sspitsyn

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/CommandProcessor.java

@@ -1938,7 +1938,7 @@ public void run(boolean prompt) {
         }
     }
 
-    static Pattern historyPattern = Pattern.compile("((!\\*)|(!\\$)|(!!-?)|(!-?[0-9][0-9]*)|(![a-zA-Z][^ ]*))");
+    static Pattern historyPattern = Pattern.compile("([\\\\]?)((!\\*)|(!\\$)|(!!-?)|(!-?[0-9][0-9]*)|(![a-zA-Z][^ ]*))");
 
     public void executeCommand(String ln, boolean putInHistory) {
         if (ln.indexOf('!') != -1) {
@@ -1951,12 +1951,20 @@ public void executeCommand(String ln, boolean putInHistory) {
                 Matcher m = historyPattern.matcher(ln);
                 int start = 0;
                 while (m.find()) {
+                    // Capture the text preceding the matched text.
                     if (m.start() > start) {
-                        result.append(ln.substring(start, m.start() - start));
+                        result.append(ln.substring(start, m.start()));
                     }
                     start = m.end();
 
-                    String cmd = m.group();
+                    if (m.group(1).length() != 0) {
+                        // This means we matched a `\` before the '!'. Don't do any history
+                        // expansion in this case. Just capture what matched after the `\`.
+                        result.append(m.group(2));
+                        continue;
+                    }
+
+                    String cmd = m.group(2);
                     if (cmd.equals("!!")) {
                         result.append((String)history.get(history.size() - 1));
                     } else if (cmd.equals("!!-")) {
@@ -2000,6 +2008,7 @@ public void executeCommand(String ln, boolean putInHistory) {
                                 String s = (String)history.get(i);
                                 if (s.startsWith(tail)) {
                                     result.append(s);
+                                    break; // only capture the most recent match in the history
                                 }
                             }
                         }

test/hotspot/jtreg/serviceability/sa/ClhsdbHistory.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import jdk.test.lib.apps.LingeredApp;
+import jdk.test.lib.Utils;
+import jtreg.SkippedException;
+
+/**
+ * @test
+ * @bug 8190198
+ * @bug 8217612
+ * @bug 8217845
+ * @summary Test clhsdb command line history support
+ * @requires vm.hasSA
+ * @library /test/lib
+ * @run main/othervm ClhsdbHistory
+ */
+
+public class ClhsdbHistory {
+
+    public static void testHistory() throws Exception {
+        System.out.println("Starting ClhsdbHistory basic test");
+
+        LingeredApp theApp = null;
+        try {
+            ClhsdbLauncher test = new ClhsdbLauncher();
+            theApp = LingeredApp.startApp();
+            System.out.println("Started LingeredApp with pid " + theApp.getPid());
+
+            List<String> cmds = List.of(
+                    "echo true",
+                    "assert false",
+                    "!!",                 // !! repeats previous command
+                    "versioncheck !$",    // !$ is last argument from previous command
+                    "assert foo bar baz",
+                    "versioncheck !*",    // !* is all arguments from previous command
+                    "versioncheck !$ !$", // !$ !$ should result in "baz baz"
+                    "assert maybe never",
+                    "!!- !*",             // !!- is the previous command, minus the last arg
+                    "!echo",              // match previous echo command, with args
+                    "assert \\!foo",      // quote the ! so it is not used for command history expansion
+                    "!10",                // match the 10th command in the history, with args
+                    "history");
+
+            // Unfortunately we can't create a map table that maps the clhsdb commands above
+            // to the expected output because the commands as you see them above won't be in
+            // the output. Instead their expanded forms will. So instead we just rely on
+            // the history output looking as expected.
+            Map<String, List<String>> expStrMap = new HashMap<>();
+            expStrMap.put("history", List.of(
+                "0 echo true",    // issued by ClhsdbLauncher
+                "1 verbose true", // issued by ClhsdbLauncher
+                "2 echo true",
+                "3 assert false",
+                "4 assert false",
+                "5 versioncheck false",
+                "6 assert foo bar baz",
+                "7 versioncheck foo bar baz",
+                "8 versioncheck baz baz",
+                "9 assert maybe never",
+                "10 assert maybe maybe never",
+                "11 echo true",
+                "12 assert !foo",
+                "13 assert maybe maybe never",
+                "14 history"));
+
+            test.run(theApp.getPid(), cmds, expStrMap, null);
+        } catch (SkippedException se) {
+            throw se;
+        } catch (Exception ex) {
+            throw new RuntimeException("Test ERROR " + ex, ex);
+        } finally {
+            LingeredApp.stopApp(theApp);
+        }
+        System.out.println("Test PASSED");
+    }
+
+    public static void main(String[] args) throws Exception {
+        testHistory();
+    }
+}