[PATCH] clean: explicitly `fflush` stdout

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Apr 8, 2020, 19:33 UTC
Message-ID: <pull.755.git.git.1586374380709.gitgitgadget@gmail.com>

From: =?UTF-8?q?=EB=A7=88=EB=88=84=EC=97=98?= <nalla@hamal.uberspace.de>

For performance reasons `stdout` is buffered by default. That leads to problems if after printing to `stdout` a read on `stdin` is performed.

For that reason interactive commands like `git clean -i` do not function properly anymore if the `stdout` is not flushed by `fflush(stdout)` before trying to read from `stdin`.

So let's precede all reads on `stdin` in `git clean -i` by flushing `stdout`.

Signed-off-by: 마누엘 <nalla@hamal.uberspace.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    Explicitly fflush stdout in git clean
    
    This is yet another patch that was funneled through a Git for Windows
    PR. It has served us well for almost five years now, and it is beyond
    time that it find its final home in core Git.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-755%2Fdscho%2Ffflush-in-git-clean-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-755/dscho/fflush-in-git-clean-v1
Pull-Request: https://github.com/git/git/pull/755

 builtin/clean.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/builtin/clean.c b/builtin/clean.c
index 5abf087e7c4..2bd06d13395 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -580,6 +580,7 @@ static int *list_and_choose(struct menu_opts *opts, struct menu_stuff *stuff)
 			       clean_get_color(CLEAN_COLOR_RESET));
 		}
 
+		fflush(stdout);
 		if (strbuf_getline_lf(&choice, stdin) != EOF) {
 			strbuf_trim(&choice);
 		} else {
@@ -662,6 +663,7 @@ static int filter_by_patterns_cmd(void)
 		clean_print_color(CLEAN_COLOR_PROMPT);
 		printf(_("Input ignore patterns>> "));
 		clean_print_color(CLEAN_COLOR_RESET);
+		fflush(stdout);
 		if (strbuf_getline_lf(&confirm, stdin) != EOF)
 			strbuf_trim(&confirm);
 		else
@@ -760,6 +762,7 @@ static int ask_each_cmd(void)
 			qname = quote_path_relative(item->string, NULL, &buf);
 			/* TRANSLATORS: Make sure to keep [y/N] as is */
 			printf(_("Remove %s [y/N]? "), qname);
+			fflush(stdout);
 			if (strbuf_getline_lf(&confirm, stdin) != EOF) {
 				strbuf_trim(&confirm);
 			} else {

base-commit: 9fadedd637b312089337d73c3ed8447e9f0aa775

-- 
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