Merge branch 'rv/alias-help'

"git cmd --help" when "cmd" is aliased used to only say "cmd is
aliased to ...".  Now it shows that to the standard error stream
and runs "git $cmd --help" where $cmd is the first word of the
alias expansion.

This could be misleading for those who alias a command with options
(e.g. with "[alias] cpn = cherry-pick -n", "git cpn --help" would
show the manual of "cherry-pick", and the reader would not be told
to pay close attention to the part that describes the "--no-commit"
option until closing the pager that showed the contents of the
manual, if the pager is configured to restore the original screen,
or would not be told at all, if the pager simply makes the message
on the standard error scroll away.

* rv/alias-help:
git-help.txt: document "git help cmd" vs "git cmd --help" for aliases
git.c: handle_alias: prepend alias info when first argument is -h
help: redirect to aliased commands for "git cmd --help"

diff --git a/Documentation/git-help.txt b/Documentation/git-help.txt
index 206e3aef648a7af8d033c60385c4b73b45b08683..aab5453bbbb239931ee2006095135c8db9f0f9ea 100644 (file)
--- a/Documentation/git-help.txt
+++ b/Documentation/git-help.txt
@@ -29,6 +29,10 @@ guide is brought up. The 'man' program is used by default for this
 purpose, but this can be overridden by other options or configuration
 variables.
 
+If an alias is given, git shows the definition of the alias on
+standard output. To get the manual page for the aliased command, use
+`git COMMAND --help`.
+
 Note that `git --help ...` is identical to `git help ...` because the
 former is internally converted into the latter.
 

diff --git a/builtin/help.c b/builtin/help.c
index d83dac283996e59b2012ed3e17f0271f93204212..7739a5c1551426fd2302aaf5daa10e454d174195 100644 (file)
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -415,9 +415,37 @@ static const char *check_git_cmd(const char* cmd)
 
        alias = alias_lookup(cmd);
        if (alias) {
-               printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
-               free(alias);
-               exit(0);
+               const char **argv;
+               int count;
+
+               /*
+                * handle_builtin() in git.c rewrites "git cmd --help"
+                * to "git help --exclude-guides cmd", so we can use
+                * exclude_guides to distinguish "git cmd --help" from
+                * "git help cmd". In the latter case, or if cmd is an
+                * alias for a shell command, just print the alias
+                * definition.
+                */
+               if (!exclude_guides || alias[0] == '!') {
+                       printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
+                       free(alias);
+                       exit(0);
+               }
+               /*
+                * Otherwise, we pretend that the command was "git
+                * word0 --help". We use split_cmdline() to get the
+                * first word of the alias, to ensure that we use the
+                * same rules as when the alias is actually
+                * used. split_cmdline() modifies alias in-place.
+                */
+               fprintf_ln(stderr, _("'%s' is aliased to '%s'"), cmd, alias);
+               count = split_cmdline(alias, &argv);
+               if (count < 0)
+                       die(_("bad alias.%s string: %s"), cmd,
+                           split_cmdline_strerror(count));
+               free(argv);
+               UNLEAK(alias);
+               return alias;
        }
 
        if (exclude_guides)

diff --git a/git.c b/git.c
index 5920f8019bb3b26db0c7c50f9ea02f8ff96230e8..adac132956e995e2dfe050b0f709ff9aaa9c7673 100644 (file)
--- a/git.c
+++ b/git.c
@@ -318,6 +318,9 @@ static int handle_alias(int *argcp, const char ***argv)
        alias_command = (*argv)[0];
        alias_string = alias_lookup(alias_command);
        if (alias_string) {
+               if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
+                       fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
+                                  alias_command, alias_string);
                if (alias_string[0] == '!') {
                        struct child_process child = CHILD_PROCESS_INIT;
                        int nongit_ok;