@matheusbsbs / matheus-bagliano / commits / b4f9282d8d

git: move seen-alias bookkeeping into handle_alias(...)

We are about to complicate the command handling by allowing *deprecated* builtins to be shadowed by aliases. We need to organize the code in order to facilitate that.[1] The code in the `while(1)` speculatively adds commands to the list before finding out if it’s an alias. Let’s instead move it inside `handle_alias(...)`—where it conceptually belongs anyway—and in turn only run this logic when we have found an alias.[2] [1]: We will do that with an additional call to `handle_alias(1)` inside the loop. *Not* moving this code leaves a blind spot; we will miss alias looping crafted via deprecated builtin names [2]: Also rename the list to a more descriptive name Based-on-patch-by: Jeff King <peff@peff.net> Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Kristoffer Haugsbakk committed Sep 17, 2025 at 22:24 UTC b4f9282d8db88619b2becac7f4ee2cad75a72ff9

1 file changed +25 -23

git.c

+25 -23

@@ -365,7 +365,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)

365 return (*argv) - orig_argv;

366 }

367

368 -static int handle_alias(struct strvec *args)

368 +static int handle_alias(struct strvec *args, struct string_list *expanded_aliases)

369 {

370 int envchanged = 0, ret = 0, saved_errno = errno;

371 int count, option_count;

@@ -376,6 +376,8 @@ static int handle_alias(struct strvec *args)

376 alias_command = args->v[0];

377 alias_string = alias_lookup(alias_command);

378 if (alias_string) {

379 + struct string_list_item *seen;

380 +

381 if (args->nr == 2 && !strcmp(args->v[1], "-h"))

382 fprintf_ln(stderr, _("'%s' is aliased to '%s'"),

383 alias_command, alias_string);

@@ -423,6 +425,25 @@ static int handle_alias(struct strvec *args)

425 if (!strcmp(alias_command, new_argv[0]))

426 die(_("recursive alias: %s"), alias_command);

427

428 + string_list_append(expanded_aliases, alias_command);

429 + seen = unsorted_string_list_lookup(expanded_aliases,

430 + new_argv[0]);

431 +

432 + if (seen) {

433 + struct strbuf sb = STRBUF_INIT;

434 + for (size_t i = 0; i < expanded_aliases->nr; i++) {

435 + struct string_list_item *item = &expanded_aliases->items[i];

436 +

437 + strbuf_addf(&sb, "\n %s", item->string);

438 + if (item == seen)

439 + strbuf_addstr(&sb, " <==");

440 + else if (i == expanded_aliases->nr - 1)

441 + strbuf_addstr(&sb, " ==>");

442 + }

443 + die(_("alias loop detected: expansion of '%s' does"

444 + " not terminate:%s"), expanded_aliases->items[0].string, sb.buf);

445 + }

446 +

447 trace_argv_printf(new_argv,

448 "trace: alias expansion: %s =>",

449 alias_command);

@@ -806,8 +827,7 @@ static void execv_dashed_external(const char **argv)

827 static int run_argv(struct strvec *args)

828 {

829 int done_alias = 0;

809 - struct string_list cmd_list = STRING_LIST_INIT_DUP;

810 - struct string_list_item *seen;

830 + struct string_list expanded_aliases = STRING_LIST_INIT_DUP;

831

832 while (1) {

833 /*

@@ -859,35 +879,17 @@ static int run_argv(struct strvec *args)

879 /* .. then try the external ones */

880 execv_dashed_external(args->v);

881

862 - seen = unsorted_string_list_lookup(&cmd_list, args->v[0]);

863 - if (seen) {

864 - struct strbuf sb = STRBUF_INIT;

865 - for (size_t i = 0; i < cmd_list.nr; i++) {

866 - struct string_list_item *item = &cmd_list.items[i];

867 -

868 - strbuf_addf(&sb, "\n %s", item->string);

869 - if (item == seen)

870 - strbuf_addstr(&sb, " <==");

871 - else if (i == cmd_list.nr - 1)

872 - strbuf_addstr(&sb, " ==>");

873 - }

874 - die(_("alias loop detected: expansion of '%s' does"

875 - " not terminate:%s"), cmd_list.items[0].string, sb.buf);

876 - }

877 -

878 - string_list_append(&cmd_list, args->v[0]);

879 -

882 /*

883 * It could be an alias -- this works around the insanity

884 * of overriding "git log" with "git show" by having

885 * alias.log = show

886 */

885 - if (!handle_alias(args))

887 + if (!handle_alias(args, &expanded_aliases))

888 break;

889 done_alias = 1;

890 }

891

890 - string_list_clear(&cmd_list, 0);

892 + string_list_clear(&expanded_aliases, 0);

893

894 return done_alias;

895 }