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.

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;
 }