Merge branch 'ah/force-pull-rebase-configuration'

"git pull" learned to warn when no pull.rebase configuration
exists, and neither --[no-]rebase nor --ff-only is given (which
would result a merge).

* ah/force-pull-rebase-configuration:
  pull: warn if the user didn't say whether to rebase or to merge

builtin/pull.c

@@ -327,6 +327,22 @@ static enum rebase_type config_get_rebase(void)
 	if (!git_config_get_value("pull.rebase", &value))
 		return parse_config_rebase("pull.rebase", value, 1);
 
+	if (opt_verbosity >= 0 &&
+	    (!opt_ff || strcmp(opt_ff, "--ff-only"))) {
+		warning(_("Pulling without specifying how to reconcile divergent branches is\n"
+			"discouraged. You can squelch this message by running one of the following\n"
+			"commands sometime before your next pull:\n"
+			"\n"
+			"  git config pull.rebase false  # merge (the default strategy)\n"
+			"  git config pull.rebase true   # rebase\n"
+			"  git config pull.ff only       # fast-forward only\n"
+			"\n"
+			"You can replace \"git config\" with \"git config --global\" to set a default\n"
+			"preference for all repositories. You can also pass --rebase, --no-rebase,\n"
+			"or --ff-only on the command line to override the configured default per\n"
+			"invocation.\n"));
+	}
+
 	return REBASE_FALSE;
 }
 

t/t5521-pull-options.sh

@@ -11,10 +11,10 @@ test_expect_success 'setup' '
 	 git commit -m one)
 '
 
-test_expect_success 'git pull -q' '
+test_expect_success 'git pull -q --no-rebase' '
 	mkdir clonedq &&
 	(cd clonedq && git init &&
-	git pull -q "../parent" >out 2>err &&
+	git pull -q --no-rebase "../parent" >out 2>err &&
 	test_must_be_empty err &&
 	test_must_be_empty out)
 '
@@ -30,10 +30,10 @@ test_expect_success 'git pull -q --rebase' '
 	test_must_be_empty out)
 '
 
-test_expect_success 'git pull' '
+test_expect_success 'git pull --no-rebase' '
 	mkdir cloned &&
 	(cd cloned && git init &&
-	git pull "../parent" >out 2>err &&
+	git pull --no-rebase "../parent" >out 2>err &&
 	test -s err &&
 	test_must_be_empty out)
 '
@@ -46,10 +46,10 @@ test_expect_success 'git pull --rebase' '
 	test_must_be_empty out)
 '
 
-test_expect_success 'git pull -v' '
+test_expect_success 'git pull -v --no-rebase' '
 	mkdir clonedv &&
 	(cd clonedv && git init &&
-	git pull -v "../parent" >out 2>err &&
+	git pull -v --no-rebase "../parent" >out 2>err &&
 	test -s err &&
 	test_must_be_empty out)
 '
@@ -62,25 +62,25 @@ test_expect_success 'git pull -v --rebase' '
 	test_must_be_empty out)
 '
 
-test_expect_success 'git pull -v -q' '
+test_expect_success 'git pull -v -q --no-rebase' '
 	mkdir clonedvq &&
 	(cd clonedvq && git init &&
-	git pull -v -q "../parent" >out 2>err &&
+	git pull -v -q --no-rebase "../parent" >out 2>err &&
 	test_must_be_empty out &&
 	test_must_be_empty err)
 '
 
-test_expect_success 'git pull -q -v' '
+test_expect_success 'git pull -q -v --no-rebase' '
 	mkdir clonedqv &&
 	(cd clonedqv && git init &&
-	git pull -q -v "../parent" >out 2>err &&
+	git pull -q -v --no-rebase "../parent" >out 2>err &&
 	test_must_be_empty out &&
 	test -s err)
 '
 test_expect_success 'git pull --cleanup errors early on invalid argument' '
 	mkdir clonedcleanup &&
 	(cd clonedcleanup && git init &&
-	test_must_fail git pull --cleanup invalid "../parent" >out 2>err &&
+	test_must_fail git pull --no-rebase --cleanup invalid "../parent" >out 2>err &&
 	test_must_be_empty out &&
 	test -s err)
 '

t/t7601-merge-pull-config.sh

@@ -27,6 +27,44 @@ test_expect_success 'setup' '
 	git tag c3
 '
 
+test_expect_success 'pull.rebase not set' '
+	git reset --hard c0 &&
+	git pull . c1 2>err &&
+	test_i18ngrep "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and pull.ff=false' '
+	git reset --hard c0 &&
+	test_config pull.ff false &&
+	git pull . c1 2>err &&
+	test_i18ngrep "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and pull.ff=only' '
+	git reset --hard c0 &&
+	test_config pull.ff only &&
+	git pull . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and --rebase given' '
+	git reset --hard c0 &&
+	git pull --rebase . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and --no-rebase given' '
+	git reset --hard c0 &&
+	git pull --no-rebase . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and --ff-only given' '
+	git reset --hard c0 &&
+	git pull --ff-only . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
 test_expect_success 'merge c1 with c2' '
 	git reset --hard c1 &&
 	test -f c0.c &&