[PATCH v3 01/10] built-in add -i/-p: treat SIGPIPE as EOF

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Jan 13, 2020, 08:29 UTC
Message-ID: <5e258a8d2bb271433902b2e44c3a30a988bbf512.1578904171.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.175.v3.git.1578904171.gitgitgadget@gmail.com>

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

As noticed by Gábor Szeder, if we want to run `git add -p` with redirected input through `test_must_fail` in the test suite, we must expect that a SIGPIPE can happen due to `stdin` coming to its end.

The appropriate action here is to ignore that signal and treat it as a regular end-of-file, otherwise the test will fail. In preparation for such a test, introduce precisely this handling of SIGPIPE into the built-in version of `git add -p`.

For good measure, teach the built-in `git add -i` the same trick: it _also_ runs a loop waiting for input, and can receive a SIGPIPE just the same (and wants to treat it as end-of-file, too).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 add-interactive.c | 3 +++
 add-patch.c       | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/add-interactive.c b/add-interactive.c
index a5bb14f2f4..3ff8400ea4 100644
--- a/add-interactive.c
+++ b/add-interactive.c
@@ -9,6 +9,7 @@
 #include "lockfile.h"
 #include "dir.h"
 #include "run-command.h"
+#include "sigchain.h"
 
 static void init_color(struct repository *r, struct add_i_state *s,
 		       const char *slot_name, char *dst,
@@ -1097,6 +1098,7 @@ int run_add_i(struct repository *r, const struct pathspec *ps)
 			->util = util;
 	}
 
+	sigchain_push(SIGPIPE, SIG_IGN);
 	init_add_i_state(&s, r);
 
 	/*
@@ -1149,6 +1151,7 @@ int run_add_i(struct repository *r, const struct pathspec *ps)
 	strbuf_release(&print_file_item_data.worktree);
 	strbuf_release(&header);
 	prefix_item_list_clear(&commands);
+	sigchain_pop(SIGPIPE);
 
 	return res;
 }
diff --git a/add-patch.c b/add-patch.c
index 46c6c183d5..9a3beed72e 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -6,6 +6,7 @@
 #include "pathspec.h"
 #include "color.h"
 #include "diff.h"
+#include "sigchain.h"
 
 enum prompt_mode_type {
 	PROMPT_MODE_CHANGE = 0, PROMPT_DELETION, PROMPT_HUNK,
@@ -1578,6 +1579,7 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
 	};
 	size_t i, binary_count = 0;
 
+	sigchain_push(SIGPIPE, SIG_IGN);
 	init_add_i_state(&s.s, r);
 
 	if (mode == ADD_P_STASH)
@@ -1612,6 +1614,7 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
 	    parse_diff(&s, ps) < 0) {
 		strbuf_release(&s.plain);
 		strbuf_release(&s.colored);
+		sigchain_pop(SIGPIPE);
 		return -1;
 	}
 
@@ -1630,5 +1633,6 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
 	strbuf_release(&s.buf);
 	strbuf_release(&s.plain);
 	strbuf_release(&s.colored);
+	sigchain_pop(SIGPIPE);
 	return 0;
 }

-- 
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