[PATCH 2/2] help -a: handle aliases with long names gracefully

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Dec 11, 2018, 14:58 UTC
Message-ID: <850cd5d15abe5b8a4356efe86ba81bc032278dce.1544540287.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.97.git.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

We take pains to determine the longest command beforehand, so that we can align the category column after printing the command names.

However, then we re-use that value when printing the aliases. If any alias name is longer than the longest command name, we consequently try to add a negative number of spaces (but `mput_char()` does not expect any negative values and simply decrements until the value is 0, i.e. it tries to add close to 2**31 spaces).

Let's fix this by adjusting the `longest` variable before printing the aliases.

This fixes https://github.com/git-for-windows/git/issues/1975.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 help.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/help.c b/help.c
index 4745b32299..ff05fd22df 100644
--- a/help.c
+++ b/help.c
@@ -83,8 +83,9 @@ static void print_command_list(const struct cmdname_help *cmds,
 
 	for (i = 0; cmds[i].name; i++) {
 		if (cmds[i].category & mask) {
+			size_t len = strlen(cmds[i].name);
 			printf("   %s   ", cmds[i].name);
-			mput_char(' ', longest - strlen(cmds[i].name));
+			mput_char(' ', longest > len ? longest - len : 1);
 			puts(_(cmds[i].help));
 		}
 	}
@@ -526,6 +527,13 @@ void list_all_cmds_help(void)
 
 	git_config(get_alias, &alias_list);
 	string_list_sort(&alias_list);
+
+	for (i = 0; i < alias_list.nr; i++) {
+		size_t len = strlen(alias_list.items[i].string);
+		if (longest < len)
+			longest = len;
+	}
+
 	if (alias_list.nr) {
 		printf("\n%s\n", _("Command aliases"));
 		ALLOC_ARRAY(aliases, alias_list.nr + 1);

-- 
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