From f4fe7b09e262bef6ac943db9bac34954eb4dd1d3 Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Thu, 18 Jun 2020 09:25:08 +0530
Subject: [PATCH 1/9] Add performance improvement option to GitSCM descriptor

---
 src/main/java/hudson/plugins/git/GitSCM.java              | 4 +++-
 src/main/resources/hudson/plugins/git/GitSCM/global.jelly | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/main/java/hudson/plugins/git/GitSCM.java b/src/main/java/hudson/plugins/git/GitSCM.java
index d10ee3c34c..3e3bd6f800 100644
--- a/src/main/java/hudson/plugins/git/GitSCM.java
+++ b/src/main/java/hudson/plugins/git/GitSCM.java
@@ -835,7 +835,6 @@ public GitClient createClient(TaskListener listener, EnvVars environment, Run<?,
 
         String gitExe = getGitExe(n, listener);
         Git git = Git.with(listener, environment).in(ws).using(gitExe);
-
         GitClient c = git.getClient();
         for (GitSCMExtension ext : extensions) {
             c = ext.decorate(this,c);
@@ -1483,6 +1482,7 @@ public static final class DescriptorImpl extends SCMDescriptor<GitSCM> {
         private boolean useExistingAccountWithSameEmail;
 //        private GitClientType defaultClientType = GitClientType.GITCLI;
         private boolean showEntireCommitSummaryInChanges;
+        private boolean enablePerformanceImprovement = true; // By default, performance is enabled in git plugin
 
         public DescriptorImpl() {
             super(GitSCM.class, GitRepositoryBrowser.class);
@@ -1606,6 +1606,8 @@ public void setUseExistingAccountWithSameEmail(boolean useExistingAccountWithSam
             this.useExistingAccountWithSameEmail = useExistingAccountWithSameEmail;
         }
 
+        public boolean isPerformanceEnabled() { return enablePerformanceImprovement; }
+
         /**
          * Old configuration of git executable - exposed so that we can
          * migrate this setting to GitTool without deprecation warnings.
diff --git a/src/main/resources/hudson/plugins/git/GitSCM/global.jelly b/src/main/resources/hudson/plugins/git/GitSCM/global.jelly
index e6b30c008f..ad9485d21e 100644
--- a/src/main/resources/hudson/plugins/git/GitSCM/global.jelly
+++ b/src/main/resources/hudson/plugins/git/GitSCM/global.jelly
@@ -16,6 +16,9 @@
     <f:entry field="showEntireCommitSummaryInChanges">
       <f:checkbox title="${%Show the entire commit summary in changes}" name="showEntireCommitSummaryInChanges" checked="${descriptor.showEntireCommitSummaryInChanges}"/>
     </f:entry>
+    <f:entry field="enablePerformanceImprovement">
+      <f:checkbox title="${%Revert performance improvement changes}" name="enablePerformanceImprovement" checked="${descriptor.enablePerformanceImprovement}"/>
+    </f:entry>
     <!--
     <f:entry title="${%Default git client implementation}" field="defaultClientType">
         <select>

From f2168cd4daee8753224a89090f0fea32219d73b5 Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Fri, 3 Jul 2020 01:22:07 +0530
Subject: [PATCH 2/9] Add documentation for opt-out switch called Preserve
 second fetch during checkout

---
 README.adoc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/README.adoc b/README.adoc
index 7c28d4e76f..5ababff278 100644
--- a/README.adoc
+++ b/README.adoc
@@ -166,6 +166,11 @@ Show the entire commit summary in changes::
   With the release of git plugin 4.0, the default was changed to show the complete change summary.
   Administrators that want to restore the old behavior may disable this setting.
 
+[[preserve-second-fetch-during-checkout]]
+Preserve second fetch during checkout::
+
+  If checked the checkout step will not avoid the second fetch.
+
 [#repository-browser]
 === Repository Browser
 

From a3912a4a5ae710ebb10f80abfccf8c116dc38fed Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Fri, 3 Jul 2020 01:22:48 +0530
Subject: [PATCH 3/9] Add an "opt-out" global switch which retains the second
 fetch With the latest fix on redundant fetch issue [JENKINS-49757], the
 second fetch in the checkout step is avoided for cases where the second fetch
 is not adding any new repository information to the existing git repository.

Enabling this switch will allow the user to preserve the second
fetch and remedy any compatibility issues.
---
 src/main/java/hudson/plugins/git/GitSCM.java    | 17 ++++++++++++++---
 .../hudson/plugins/git/GitSCM/global.jelly      |  4 ++--
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/main/java/hudson/plugins/git/GitSCM.java b/src/main/java/hudson/plugins/git/GitSCM.java
index 86179989f2..d4d0e879c6 100644
--- a/src/main/java/hudson/plugins/git/GitSCM.java
+++ b/src/main/java/hudson/plugins/git/GitSCM.java
@@ -438,6 +438,11 @@ public boolean isUseExistingAccountWithSameEmail() {
         return (gitDescriptor != null && gitDescriptor.isUseExistingAccountWithSameEmail());
     }
 
+    public boolean isRedundantFetchAllowed() {
+        DescriptorImpl gitDescriptor = getDescriptor();
+        return (gitDescriptor != null && gitDescriptor.isRedundantFetchAllowed());
+    }
+
     @Whitelisted
     public BuildChooser getBuildChooser() {
         BuildChooser bc;
@@ -1132,7 +1137,9 @@ private void retrieveChanges(Run build, GitClient git, TaskListener listener) th
                 cmd.execute();
                 // determine if second fetch is required
                 CloneOption option = extensions.get(CloneOption.class);
-                removeRedundantFetch = determineRedundantFetch(option, rc);
+                if (!isRedundantFetchAllowed()) {
+                    removeRedundantFetch = determineRedundantFetch(option, rc);
+                }
             } catch (GitException ex) {
                 ex.printStackTrace(listener.error("Error cloning remote repo '" + rc.getName() + "'"));
                 throw new AbortException("Error cloning remote repo '" + rc.getName() + "'");
@@ -1518,7 +1525,7 @@ public static final class DescriptorImpl extends SCMDescriptor<GitSCM> {
         private boolean useExistingAccountWithSameEmail;
 //        private GitClientType defaultClientType = GitClientType.GITCLI;
         private boolean showEntireCommitSummaryInChanges;
-        private boolean enablePerformanceImprovement = true; // By default, performance is enabled in git plugin
+        private boolean allowSecondFetch;
 
         public DescriptorImpl() {
             super(GitSCM.class, GitRepositoryBrowser.class);
@@ -1642,7 +1649,11 @@ public void setUseExistingAccountWithSameEmail(boolean useExistingAccountWithSam
             this.useExistingAccountWithSameEmail = useExistingAccountWithSameEmail;
         }
 
-        public boolean isPerformanceEnabled() { return enablePerformanceImprovement; }
+        public boolean isRedundantFetchAllowed() { return allowSecondFetch; }
+
+        public void setAllowSecondFetch(boolean allowSecondFetch) {
+            this.allowSecondFetch = allowSecondFetch;
+        }
 
         /**
          * Old configuration of git executable - exposed so that we can
diff --git a/src/main/resources/hudson/plugins/git/GitSCM/global.jelly b/src/main/resources/hudson/plugins/git/GitSCM/global.jelly
index ad9485d21e..9964c5ee2f 100644
--- a/src/main/resources/hudson/plugins/git/GitSCM/global.jelly
+++ b/src/main/resources/hudson/plugins/git/GitSCM/global.jelly
@@ -16,8 +16,8 @@
     <f:entry field="showEntireCommitSummaryInChanges">
       <f:checkbox title="${%Show the entire commit summary in changes}" name="showEntireCommitSummaryInChanges" checked="${descriptor.showEntireCommitSummaryInChanges}"/>
     </f:entry>
-    <f:entry field="enablePerformanceImprovement">
-      <f:checkbox title="${%Revert performance improvement changes}" name="enablePerformanceImprovement" checked="${descriptor.enablePerformanceImprovement}"/>
+    <f:entry field="allowSecondFetch">
+      <f:checkbox title="${%Preserve second fetch during checkout}" name="allowSecondFetch" checked="${descriptor.allowSecondFetch}"/>
     </f:entry>
     <!--
     <f:entry title="${%Default git client implementation}" field="defaultClientType">

From 533fd5d33cdf45c2df4b7b9ef54372de7a1eac4c Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Fri, 3 Jul 2020 01:33:12 +0530
Subject: [PATCH 4/9] Add an automated test case for retaining second fetch
 from global swithc

---
 .../java/hudson/plugins/git/GitSCMTest.java   | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/test/java/hudson/plugins/git/GitSCMTest.java b/src/test/java/hudson/plugins/git/GitSCMTest.java
index efa3ecb5e8..8f817ac855 100644
--- a/src/test/java/hudson/plugins/git/GitSCMTest.java
+++ b/src/test/java/hudson/plugins/git/GitSCMTest.java
@@ -517,6 +517,42 @@ public void testRetainRedundantFetch() throws Exception {
         assertRedundantFetchIsUsed(build, refspec);
     }
 
+    /*
+    * When "Preserve second fetch during checkout" is checked in during configuring Jenkins,
+    * the second fetch should be retained
+    */
+    @Test
+    @Issue("JENKINS-49757")
+    public void testRetainRedundantFetchIfSecondFetchIsAllowed() throws Exception {
+        String refspec = "+refs/heads/*:refs/remotes/*";
+        List<UserRemoteConfig> repos = new ArrayList<>();
+        repos.add(new UserRemoteConfig(testRepo.gitDir.getAbsolutePath(), "origin", refspec, null));
+
+        /* Without honor refspec on initial clone */
+        FreeStyleProject projectWithMaster = setupProject(repos, Collections.singletonList(new BranchSpec("master")), null, false, null);
+
+        GitSCM scm = (GitSCM) projectWithMaster.getScm();
+        final DescriptorImpl descriptor = (DescriptorImpl) scm.getDescriptor();
+        assertThat("Redundant fetch is skipped by default", scm.isRedundantFetchAllowed(), is(false));
+        descriptor.setAllowSecondFetch(true);
+        assertThat("Redundant fetch should be allowed", scm.isRedundantFetchAllowed(), is(true));
+
+        if (random.nextBoolean()) {
+            /* Randomly enable shallow clone, should not alter test assertions */
+            CloneOption cloneOptionMaster = new CloneOption(false, null, null);
+            cloneOptionMaster.setDepth(1);
+            ((GitSCM) projectWithMaster.getScm()).getExtensions().add(cloneOptionMaster);
+        }
+
+        // create initial commit
+        final String commitFile1 = "commitFile1";
+        commit(commitFile1, johnDoe, "Commit in master");
+
+        FreeStyleBuild build = build(projectWithMaster, Result.SUCCESS);
+
+        assertRedundantFetchIsUsed(build, refspec);
+    }
+
     // Checks if the second fetch is being avoided
     private void assertRedundantFetchIsSkipped(FreeStyleBuild build, String refSpec) throws IOException {
         assertRedundantFetchCount(build, refSpec, 1);

From a01665ec0d9c98dc5a0490a741c450b2e1d7010b Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <31189405+rishabhBudhouliya@users.noreply.github.com>
Date: Fri, 3 Jul 2020 11:51:29 +0530
Subject: [PATCH 5/9] Update README.adoc with a better message

Co-authored-by: Mark Waite <mark.earl.waite@gmail.com>
---
 README.adoc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/README.adoc b/README.adoc
index 5ababff278..05dd1e949b 100644
--- a/README.adoc
+++ b/README.adoc
@@ -170,6 +170,11 @@ Show the entire commit summary in changes::
 Preserve second fetch during checkout::
 
   If checked the checkout step will not avoid the second fetch.
+  Git plugin versions prior to git plugin 4.4 would perform two fetch operations for each repository checkout.
+  Git plugin 4.4 removes the redundant fetch operation.
+  Enabling this option will restore the redundant fetch operation.
+  This setting is only needed if there is a bug in the redundant fetch removal logic.
+  If you enable this setting, please report a git plugin issue that describes why you needed to enable it.
 
 [#repository-browser]
 === Repository Browser

From 2cbd0e0dc3059c9ea7ca881698d6a641ceb9a8b2 Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Fri, 3 Jul 2020 12:11:42 +0530
Subject: [PATCH 6/9] Undo whitespace change in GitSCM

---
 src/main/java/hudson/plugins/git/GitSCM.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/main/java/hudson/plugins/git/GitSCM.java b/src/main/java/hudson/plugins/git/GitSCM.java
index d4d0e879c6..3f3a58cd8f 100644
--- a/src/main/java/hudson/plugins/git/GitSCM.java
+++ b/src/main/java/hudson/plugins/git/GitSCM.java
@@ -440,7 +440,7 @@ public boolean isUseExistingAccountWithSameEmail() {
 
     public boolean isRedundantFetchAllowed() {
         DescriptorImpl gitDescriptor = getDescriptor();
-        return (gitDescriptor != null && gitDescriptor.isRedundantFetchAllowed());
+        return (gitDescriptor != null && gitDescriptor.isAllowSecondFetch());
     }
 
     @Whitelisted
@@ -840,6 +840,7 @@ public GitClient createClient(TaskListener listener, EnvVars environment, Run<?,
 
         String gitExe = getGitExe(n, listener);
         Git git = Git.with(listener, environment).in(ws).using(gitExe);
+
         GitClient c = git.getClient();
         for (GitSCMExtension ext : extensions) {
             c = ext.decorate(this,c);
@@ -1649,7 +1650,7 @@ public void setUseExistingAccountWithSameEmail(boolean useExistingAccountWithSam
             this.useExistingAccountWithSameEmail = useExistingAccountWithSameEmail;
         }
 
-        public boolean isRedundantFetchAllowed() { return allowSecondFetch; }
+        public boolean isAllowSecondFetch() { return allowSecondFetch; }
 
         public void setAllowSecondFetch(boolean allowSecondFetch) {
             this.allowSecondFetch = allowSecondFetch;

From ed6bbb53729b670a489bb42b265264365e17341c Mon Sep 17 00:00:00 2001
From: Mark Waite <mark.earl.waite@gmail.com>
Date: Fri, 3 Jul 2020 21:22:50 -0600
Subject: [PATCH 7/9] Fix my merge error

---
 src/main/java/hudson/plugins/git/GitSCM.java | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/main/java/hudson/plugins/git/GitSCM.java b/src/main/java/hudson/plugins/git/GitSCM.java
index 9e63ef5916..ebb6aca57a 100644
--- a/src/main/java/hudson/plugins/git/GitSCM.java
+++ b/src/main/java/hudson/plugins/git/GitSCM.java
@@ -441,6 +441,7 @@ public boolean isUseExistingAccountWithSameEmail() {
     public boolean isHideCredentials() {
         DescriptorImpl gitDescriptor = getDescriptor();
         return gitDescriptor != null && gitDescriptor.isHideCredentials();
+    }
 
     public boolean isRedundantFetchAllowed() {
         DescriptorImpl gitDescriptor = getDescriptor();

From e06c68346ae3ec93f0b34077cc8c8edd6862c9af Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Sat, 4 Jul 2020 15:47:40 +0530
Subject: [PATCH 8/9] Make allowSecondFetch consistent to fix UI persistence
 issue

---
 src/main/java/hudson/plugins/git/GitSCM.java     | 4 ++--
 src/test/java/hudson/plugins/git/GitSCMTest.java | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/java/hudson/plugins/git/GitSCM.java b/src/main/java/hudson/plugins/git/GitSCM.java
index ebb6aca57a..50be4d3749 100644
--- a/src/main/java/hudson/plugins/git/GitSCM.java
+++ b/src/main/java/hudson/plugins/git/GitSCM.java
@@ -443,7 +443,7 @@ public boolean isHideCredentials() {
         return gitDescriptor != null && gitDescriptor.isHideCredentials();
     }
 
-    public boolean isRedundantFetchAllowed() {
+    public boolean isAllowSecondFetch() {
         DescriptorImpl gitDescriptor = getDescriptor();
         return (gitDescriptor != null && gitDescriptor.isAllowSecondFetch());
     }
@@ -1147,7 +1147,7 @@ private void retrieveChanges(Run build, GitClient git, TaskListener listener) th
                 cmd.execute();
                 // determine if second fetch is required
                 CloneOption option = extensions.get(CloneOption.class);
-                if (!isRedundantFetchAllowed()) {
+                if (!isAllowSecondFetch()) {
                     removeRedundantFetch = determineRedundantFetch(option, rc);
                 }
             } catch (GitException ex) {
diff --git a/src/test/java/hudson/plugins/git/GitSCMTest.java b/src/test/java/hudson/plugins/git/GitSCMTest.java
index c2b939f3c3..75f76e145e 100644
--- a/src/test/java/hudson/plugins/git/GitSCMTest.java
+++ b/src/test/java/hudson/plugins/git/GitSCMTest.java
@@ -533,9 +533,9 @@ public void testRetainRedundantFetchIfSecondFetchIsAllowed() throws Exception {
 
         GitSCM scm = (GitSCM) projectWithMaster.getScm();
         final DescriptorImpl descriptor = (DescriptorImpl) scm.getDescriptor();
-        assertThat("Redundant fetch is skipped by default", scm.isRedundantFetchAllowed(), is(false));
+        assertThat("Redundant fetch is skipped by default", scm.isAllowSecondFetch(), is(false));
         descriptor.setAllowSecondFetch(true);
-        assertThat("Redundant fetch should be allowed", scm.isRedundantFetchAllowed(), is(true));
+        assertThat("Redundant fetch should be allowed", scm.isAllowSecondFetch(), is(true));
 
         if (random.nextBoolean()) {
             /* Randomly enable shallow clone, should not alter test assertions */

From 63c4ebd0ee6b37e3cb56dd400ecabc99d98a11e9 Mon Sep 17 00:00:00 2001
From: Rishabh Budhouliya <rishabhbudhouliya@gmail.com>
Date: Sat, 4 Jul 2020 15:58:19 +0530
Subject: [PATCH 9/9] Replace redundant fetch with second fetch

---
 src/main/java/hudson/plugins/git/GitSCM.java | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/java/hudson/plugins/git/GitSCM.java b/src/main/java/hudson/plugins/git/GitSCM.java
index 50be4d3749..cccf596a8c 100644
--- a/src/main/java/hudson/plugins/git/GitSCM.java
+++ b/src/main/java/hudson/plugins/git/GitSCM.java
@@ -1125,7 +1125,7 @@ public EnvVars getEnvironment() {
     private void retrieveChanges(Run build, GitClient git, TaskListener listener) throws IOException, InterruptedException {
         final PrintStream log = listener.getLogger();
 
-        boolean removeRedundantFetch = false;
+        boolean removeSecondFetch = false;
         List<RemoteConfig> repos = getParamExpandedRepos(build, listener);
         if (repos.isEmpty())    return; // defensive check even though this is an invalid configuration
 
@@ -1148,7 +1148,7 @@ private void retrieveChanges(Run build, GitClient git, TaskListener listener) th
                 // determine if second fetch is required
                 CloneOption option = extensions.get(CloneOption.class);
                 if (!isAllowSecondFetch()) {
-                    removeRedundantFetch = determineRedundantFetch(option, rc);
+                    removeSecondFetch = determineSecondFetch(option, rc);
                 }
             } catch (GitException ex) {
                 ex.printStackTrace(listener.error("Error cloning remote repo '" + rc.getName() + "'"));
@@ -1157,7 +1157,7 @@ private void retrieveChanges(Run build, GitClient git, TaskListener listener) th
         }
 
         for (RemoteConfig remoteRepository : repos) {
-            if (remoteRepository.equals(repos.get(0)) && removeRedundantFetch){
+            if (remoteRepository.equals(repos.get(0)) && removeSecondFetch){
                 log.println("Avoid second fetch");
                 continue;
             }
@@ -1172,7 +1172,7 @@ private void retrieveChanges(Run build, GitClient git, TaskListener listener) th
         }
     }
 
-    private boolean determineRedundantFetch(CloneOption option, @NonNull RemoteConfig rc) {
+    private boolean determineSecondFetch(CloneOption option, @NonNull RemoteConfig rc) {
         List<RefSpec> initialFetchRefSpecs = rc.getFetchRefSpecs();
         boolean isDefaultRefspec = true; // default refspec is any refspec with "refs/heads/" mapping
         boolean removeSecondFetch = true;