From 8489ebce32f4b6cf5c1c1120fd474e26f7659db7 Mon Sep 17 00:00:00 2001
From: Ron Yorston <rmy@pobox.com>
Date: Sat, 13 Feb 2021 10:17:16 +0000
Subject: win32: code shrink

Rewrite the recent change to tab completion so it only needs
one call to sprintf.  Then replace sprintf with strcpy/stpcpy,
both there and in a couple of other places.

Saves 40 bytes.
---
 libbb/lineedit.c | 20 +++++++++++++++-----
 shell/ash.c      |  2 +-
 win32/mingw.c    |  2 +-
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 4802b46b4..55141e141 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -1251,6 +1251,8 @@ static NOINLINE void input_tab(smallint *lastWasTab)
 	unsigned match_pfx_len = match_pfx_len;
 #if ENABLE_PLATFORM_MINGW32
 	unsigned orig_pfx_len;
+	char *target;
+	const char *source;
 #endif
 	int find_type;
 # if ENABLE_UNICODE_SUPPORT
@@ -1393,13 +1395,21 @@ static NOINLINE void input_tab(smallint *lastWasTab)
 		/* save tail */
 		strcpy(match_buf, &command_ps[cursor]);
 		/* add match and tail */
-#if ENABLE_PLATFORM_MINGW32
+#  if ENABLE_PLATFORM_MINGW32
 		if (match_pfx_len == orig_pfx_len) {
-			sprintf(&command_ps[cursor-match_pfx_len], "%s%s",
-					chosen_match, match_buf);
-		} else
-#endif
+			/* replace match prefix to allow for altered case */
+			target = &command_ps[cursor-match_pfx_len];
+			source = chosen_match;
+		}
+		else {
+			/* only replace tail of match if special characters are quoted */
+			target = &command_ps[cursor];
+			source = chosen_match + match_pfx_len;
+		}
+		strcpy(stpcpy(target, source), match_buf);
+#  else
 		sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, match_buf);
+#  endif
 		command_len = strlen(command_ps);
 		/* new pos */
 		pos = cursor + len_found - match_pfx_len;
diff --git a/shell/ash.c b/shell/ash.c
index c400612d9..f8a18cdc5 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2119,7 +2119,7 @@ stack_add_system_drive(const char *path)
 	const char *sd = need_system_drive(path);
 	char *p = growstackto(strlen(path) + 5 + (sd ? strlen(sd) : 0));
 
-	sprintf(p, "%s%s", sd ?: "", path);
+	strcpy(stpcpy(p, sd ?: ""), path);
 	return p;
 }
 #endif
diff --git a/win32/mingw.c b/win32/mingw.c
index a6362333d..75635fdf1 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -1729,7 +1729,7 @@ char *alloc_system_drive(const char *path)
 {
 	const char *sd = need_system_drive(path);
 	char *s = xmalloc(strlen(path) + 5 + (sd ? strlen(sd) : 0));
-	sprintf(s, "%s%s", sd ?: "", path);
+	strcpy(stpcpy(s, sd ?: ""), path);
 	return s;
 }
 
-- 
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