Remove old git tests and related conditionals

Red Hat Enterprise Linux 7 includes command line git 1.8.  No other
supported operating system includes a command line git version older
than 2.20.

Debian 10 is the oldest command line git version on a supported operating
system with command line git 2.20.  Ubuntu 20 has a newer command line
git version.

Author: MarkEWaite

src/main/java/org/jenkinsci/plugins/gitclient/CliGitAPIImpl.java

@@ -1499,10 +1499,6 @@ public void execute() throws GitException, InterruptedException {
                     }
                     if (isAtLeastVersion(1, 8, 4, 0)) {
                         args.add("--depth=" + depth);
-                    } else {
-                        listener.getLogger()
-                                .println(
-                                        "[WARNING] Git client older than 1.8.4 doesn't support shallow submodule updates. This flag is ignored.");
                     }
                 }
 
@@ -1749,7 +1745,6 @@ public boolean isBareRepository(String GIT_DIR) throws GitException, Interrupted
 
     /**
      * Returns true if this repository is configured as a shallow clone.
-     * Shallow clone requires command line git 1.9 or later.
      * @return true if this repository is configured as a shallow clone
      */
     public boolean isShallowRepository() {
@@ -2932,10 +2927,6 @@ public void execute() throws GitException, InterruptedException {
                     args.add("--tags");
                 }
 
-                if (!isAtLeastVersion(1, 9, 0, 0) && isShallowRepository()) {
-                    throw new GitException("Can't push from shallow repository using git client older than 1.9.0");
-                }
-
                 StandardCredentials cred = credentials.get(remote.toPrivateString());
                 if (cred == null) {
                     cred = defaultCredentials;

src/main/java/org/jenkinsci/plugins/gitclient/GitClient.java

@@ -653,8 +653,7 @@ Map<String, ObjectId> getRemoteReferences(String remoteRepoUrl, String pattern,
      * @param remoteRepoUrl Remote repository URL.
      * @param pattern       Only references matching the given pattern are displayed.
      * @return a map of reference names and their underlying references. Empty if none or if the remote does not report
-     * symbolic references (i.e. Git 1.8.4 or earlier) or if the client does not support reporting symbolic references
-     * (e.g. command line Git prior to 2.8.0).
+     * symbolic references or if the command line git version does not support reporting symbolic references.
      * @throws hudson.plugins.git.GitException if underlying git operation fails.
      * @throws java.lang.InterruptedException  if interrupted.
      */

src/main/java/org/jenkinsci/plugins/gitclient/SubmoduleUpdateCommand.java

@@ -16,11 +16,11 @@ public interface SubmoduleUpdateCommand extends GitCommand {
     /**
      * If set true and if the git version supports it, update the
      * submodules to the tip of the branch rather than to a specific
-     * SHA1.  Refer to git documentation for details.  First available
-     * in command line git 1.8.2.  Default is to update to a specific
-     * SHA1 (compatible with previous versions of git)
+     * SHA1.  Refer to git documentation for details.  Default is to
+     * update to a specific SHA1 (compatible with previous versions of
+     * git)
      *
-     * @param remoteTracking if true, will update the submodule to the tip of the branch requested (requires git>=1.8.2)
+     * @param remoteTracking if true, will update the submodule to the tip of the branch requested
      * @return a {@link org.jenkinsci.plugins.gitclient.SubmoduleUpdateCommand} object.
      */
     SubmoduleUpdateCommand remoteTracking(boolean remoteTracking);
@@ -63,7 +63,7 @@ public interface SubmoduleUpdateCommand extends GitCommand {
      * Only clone the most recent history, not preceding history.  Depth of the
      * shallow clone is controlled by the #depth method.
      *
-     * @param shallow boolean controlling whether the clone is shallow (requires git>=1.8.4)
+     * @param shallow boolean controlling whether the clone is shallow
      * @return a {@link org.jenkinsci.plugins.gitclient.SubmoduleUpdateCommand} object.
      */
     SubmoduleUpdateCommand shallow(boolean shallow);
@@ -72,7 +72,7 @@ public interface SubmoduleUpdateCommand extends GitCommand {
      * When shallow cloning, allow for a depth to be set in cases where you need more than the immediate last commit.
      * Has no effect if shallow is set to false (default).
      *
-     * @param depth number of revisions to be included in shallow clone (requires git>=1.8.4)
+     * @param depth number of revisions to be included in shallow clone
      * @return a {@link org.jenkinsci.plugins.gitclient.SubmoduleUpdateCommand} object.
      */
     SubmoduleUpdateCommand depth(Integer depth);

src/test/java/org/jenkinsci/plugins/gitclient/GitAPIForCliGitTest.java

@@ -1,7 +1,6 @@
 package org.jenkinsci.plugins.gitclient;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import hudson.Util;
@@ -156,21 +155,10 @@ public void testPushFromShallowClone() throws Exception {
         testGitClient.commit("commit2");
         ObjectId sha1 = workspace.head();
 
-        try {
-            testGitClient.push("origin", defaultBranchName);
-            assertTrue(
-                    "git < 1.9.0 can push from shallow repository",
-                    workspace.cgit().isAtLeastVersion(1, 9, 0, 0));
-            String remoteSha1 =
-                    remote.launchCommand("git", "rev-parse", defaultBranchName).substring(0, 40);
-            assertEquals(sha1.name(), remoteSha1);
-        } catch (GitException ge) {
-            // expected for git cli < 1.9.0
-            assertExceptionMessageContains(ge, "push from shallow repository");
-            assertFalse(
-                    "git >= 1.9.0 can't push from shallow repository",
-                    workspace.cgit().isAtLeastVersion(1, 9, 0, 0));
-        }
+        testGitClient.push("origin", defaultBranchName);
+        String remoteSha1 =
+                remote.launchCommand("git", "rev-parse", defaultBranchName).substring(0, 40);
+        assertEquals(sha1.name(), remoteSha1);
     }
 
     private void assertExceptionMessageContains(GitException ge, String expectedSubstring) {

src/test/java/org/jenkinsci/plugins/gitclient/GitClientFetchTest.java

@@ -284,42 +284,18 @@ public void test_fetch() throws Exception {
                 .getHeadRev(bareWorkspace.getGitFileDir().getAbsolutePath(), defaultBranchName);
         assertThat("bare5 != working5", bareCommit5, is(commit5));
 
-        /* Fetch into newArea repo with null RefSpec - should only
-         * pull tags, not commits in git versions prior to git 1.9.0.
-         * In git 1.9.0, fetch -t pulls tags and versions. */
+        /* Fetch into newArea repo with null RefSpec. */
         newAreaWorkspace.getGitClient().fetch("origin", null, null);
         assertThat(
                 "null refSpec fetch modified local repo",
                 newAreaWorkspace.getGitClient().revParse("HEAD"),
                 is(bareCommit4));
-        ObjectId expectedHead = bareCommit4;
-        if (gitImplName.startsWith("jgit") || workspace.cgit().isAtLeastVersion(1, 9, 0, 0)) {
-            newAreaWorkspace
-                    .getGitClient()
-                    .merge()
-                    .setRevisionToMerge(bareCommit5)
-                    .execute();
-            expectedHead = bareCommit5;
-        } else {
-            GitException gitException = assertThrows(GitException.class, () -> newAreaWorkspace
-                    .getGitClient()
-                    .merge()
-                    .setRevisionToMerge(bareCommit5)
-                    .execute());
-            assertThat(
-                    gitException.getMessage(),
-                    anyOf(
-                            containsString("Could not merge"),
-                            containsString("not something we can merge"),
-                            containsString("does not point to a commit")));
-        }
-        /* Assert that expected change is in repo after merge.  With
-         * git 1.7 and 1.8, it should be bareCommit4.  With git 1.9
-         * and later, it should be bareCommit5. */
+        ObjectId expectedHead = bareCommit5;
+        newAreaWorkspace.getGitClient().merge().setRevisionToMerge(bareCommit5).execute();
         assertThat(
                 "null refSpec fetch modified local repo",
                 newAreaWorkspace.getGitClient().revParse("HEAD"),
-                is(expectedHead));
+                is(bareCommit5));
     }
 
     @Test

src/test/java/org/jenkinsci/plugins/gitclient/GitClientSecurityTest.java

@@ -63,10 +63,6 @@ public GitClientSecurityTest(final String badRemoteUrl, final boolean enableRemo
         this.enableRemoteCheckUrl = enableRemoteCheckUrl;
     }
 
-    /* Capabilities of command line git in current environment */
-    private static final boolean CLI_GIT_SUPPORTS_OPERAND_SEPARATOR;
-    private static final boolean CLI_GIT_SUPPORTS_SYMREF;
-
     static {
         CliGitAPIImpl tempGitClient;
         try {
@@ -77,13 +73,6 @@ public GitClientSecurityTest(final String badRemoteUrl, final boolean enableRemo
         } catch (Exception e) {
             tempGitClient = null;
         }
-        if (tempGitClient != null) {
-            CLI_GIT_SUPPORTS_OPERAND_SEPARATOR = tempGitClient.isAtLeastVersion(2, 8, 0, 0);
-            CLI_GIT_SUPPORTS_SYMREF = tempGitClient.isAtLeastVersion(2, 8, 0, 0);
-        } else {
-            CLI_GIT_SUPPORTS_OPERAND_SEPARATOR = false;
-            CLI_GIT_SUPPORTS_SYMREF = false;
-        }
     }
 
     private static final Random CONFIG_RANDOM = new Random();
@@ -100,23 +89,14 @@ public GitClientSecurityTest(final String badRemoteUrl, final boolean enableRemo
      *
      * This function returns a randomly selected value to enable or
      * disable the repository URL check based on the contents of the
-     * attack string. If remote check is selected to be disabled and
-     * the command line git implementation does not have full support
-     * for the '--' separator between options and operands and the
+     * attack string. If remote check is selected to be disabled and the
      * attack is one of a known list of strings, then this function
      * will always return 'true' so that the remote checks will be
      * enabled.
-     *
-     * Returning 'false' in those cases on certain older command line
-     * git implementations (git 1.8.3 on CentOS 7, git 2.7.4 on Ubuntu
-     * 16) would cause the tested code to not throw an exception
-     * because those command line git versions do not fully support
-     * '--' to separate options and operands.
      */
     private static boolean enableRemoteCheck(String attack) {
         boolean enabled = CONFIG_RANDOM.nextBoolean();
         if (!enabled
-                && !CLI_GIT_SUPPORTS_OPERAND_SEPARATOR
                 && (attack.equals("-q")
                         || attack.equals("--quiet")
                         || attack.equals("-t")
@@ -298,9 +278,6 @@ public void testGetRemoteReferences_SECURITY_1534() {
     @Test
     @Issue("SECURITY-1534")
     public void testGetRemoteSymbolicReferences_SECURITY_1534() {
-        if (!CLI_GIT_SUPPORTS_SYMREF) {
-            return;
-        }
         String expectedMessage = enableRemoteCheckUrl ? "Invalid remote URL: " + badRemoteUrl : badRemoteUrl.trim();
         GitException e = assertThrows(
                 GitException.class, () -> gitClient.getRemoteSymbolicReferences(badRemoteUrl, DEFAULT_BRANCH_NAME));