lineedit: disable window size tracking in default configuration

SIGWINCH isn't available on Microsoft Windows.  Make the use of
SIGWINCH configurable and disable it by default.

4 files changed, 23 insertions, 4 deletions

diff --git a/configs/mingw32_defconfig b/configs/mingw32_defconfig
index 7c56866a2..265b184f9 100644
--- a/configs/mingw32_defconfig
+++ b/configs/mingw32_defconfig
@@ -103,6 +103,7 @@ CONFIG_FEATURE_REVERSE_SEARCH=y
 CONFIG_FEATURE_TAB_COMPLETION=y
 CONFIG_FEATURE_USERNAME_COMPLETION=y
 CONFIG_FEATURE_EDITING_FANCY_PROMPT=y
+# CONFIG_FEATURE_EDITING_WINCH is not set
 # CONFIG_FEATURE_EDITING_ASK_TERMINAL is not set
 # CONFIG_LOCALE_SUPPORT is not set
 # CONFIG_UNICODE_SUPPORT is not set
@@ -1082,6 +1083,7 @@ CONFIG_ASH_NOCONSOLE=y
 # CONFIG_HUSH is not set
 # CONFIG_HUSH_BASH_COMPAT is not set
 # CONFIG_HUSH_BRACE_EXPANSION is not set
+# CONFIG_HUSH_LINENO_VAR is not set
 # CONFIG_HUSH_BASH_SOURCE_CURDIR is not set
 # CONFIG_HUSH_INTERACTIVE is not set
 # CONFIG_HUSH_SAVEHISTORY is not set
diff --git a/configs/mingw64_defconfig b/configs/mingw64_defconfig
index 3261d17b8..aa355ae66 100644
--- a/configs/mingw64_defconfig
+++ b/configs/mingw64_defconfig
@@ -103,6 +103,7 @@ CONFIG_FEATURE_REVERSE_SEARCH=y
 CONFIG_FEATURE_TAB_COMPLETION=y
 CONFIG_FEATURE_USERNAME_COMPLETION=y
 CONFIG_FEATURE_EDITING_FANCY_PROMPT=y
+# CONFIG_FEATURE_EDITING_WINCH is not set
 # CONFIG_FEATURE_EDITING_ASK_TERMINAL is not set
 # CONFIG_LOCALE_SUPPORT is not set
 # CONFIG_UNICODE_SUPPORT is not set
@@ -1082,6 +1083,7 @@ CONFIG_ASH_CMDCMD=y
 # CONFIG_HUSH is not set
 # CONFIG_HUSH_BASH_COMPAT is not set
 # CONFIG_HUSH_BRACE_EXPANSION is not set
+# CONFIG_HUSH_LINENO_VAR is not set
 # CONFIG_HUSH_BASH_SOURCE_CURDIR is not set
 # CONFIG_HUSH_INTERACTIVE is not set
 # CONFIG_HUSH_SAVEHISTORY is not set
diff --git a/libbb/Config.src b/libbb/Config.src
index 3c1b064b6..fdf8bbb28 100644
--- a/libbb/Config.src
+++ b/libbb/Config.src
@@ -149,6 +149,11 @@ config FEATURE_EDITING_FANCY_PROMPT
         Setting this option allows for prompts to use things like \w and
         \$ and escape codes.
 
+config FEATURE_EDITING_WINCH
+        bool "Enable automatic tracking of window size changes"
+        default y
+        depends on FEATURE_EDITING
+
 config FEATURE_EDITING_ASK_TERMINAL
         bool "Query cursor position from terminal"
         default n
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index f22f5768f..b9ba71242 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -151,9 +151,11 @@ struct lineedit_statics {
         unsigned num_matches;
 #endif
 
+#if ENABLE_FEATURE_EDITING_WINCH
         unsigned SIGWINCH_saved;
         volatile unsigned SIGWINCH_count;
         volatile smallint ok_to_redraw;
+#endif
 
 #if ENABLE_FEATURE_EDITING_VI
 # define DELBUFSIZ 128
@@ -165,8 +167,10 @@ struct lineedit_statics {
         smallint sent_ESC_br6n;
 #endif
 
+#if ENABLE_FEATURE_EDITING_WINCH
         /* Largish struct, keeping it last results in smaller code */
         struct sigaction SIGWINCH_handler;
+#endif
 };
 
 /* See lineedit_ptr_hack.c */
@@ -2092,6 +2096,7 @@ static void parse_and_put_prompt(const char *prmt_ptr)
 }
 #endif
 
+#if ENABLE_FEATURE_EDITING_WINCH
 static void cmdedit_setwidth(void)
 {
         int new_y;
@@ -2116,6 +2121,7 @@ static void win_changed(int nsig UNUSED_PARAM)
                 S.SIGWINCH_count++;
         }
 }
+#endif
 
 static int lineedit_read_key(char *read_key_buffer, int timeout)
 {
@@ -2134,9 +2140,9 @@ static int lineedit_read_key(char *read_key_buffer, int timeout)
                  *
                  * Note: read_key sets errno to 0 on success.
                  */
-                S.ok_to_redraw = 1;
+                IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 1;)
                 ic = read_key(STDIN_FILENO, read_key_buffer, timeout);
-                S.ok_to_redraw = 0;
+                IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 0;)
                 if (errno) {
 #if ENABLE_UNICODE_SUPPORT
                         if (errno == EAGAIN && unicode_idx != 0)
@@ -2476,11 +2482,12 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
         parse_and_put_prompt(prompt);
         ask_terminal();
 
+#if ENABLE_FEATURE_EDITING_WINCH
         /* Install window resize handler (NB: after *all* init is complete) */
         S.SIGWINCH_handler.sa_handler = win_changed;
         S.SIGWINCH_handler.sa_flags = SA_RESTART;
         sigaction(SIGWINCH, &S.SIGWINCH_handler, &S.SIGWINCH_handler);
-
+#endif
         read_key_buffer[0] = 0;
         while (1) {
                 /*
@@ -2492,6 +2499,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                  * in one place.
                  */
                 int32_t ic, ic_raw;
+#if ENABLE_FEATURE_EDITING_WINCH
                 unsigned count;
 
                 count = S.SIGWINCH_count;
@@ -2499,7 +2507,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                         S.SIGWINCH_saved = count;
                         cmdedit_setwidth();
                 }
-
+#endif
                 ic = ic_raw = lineedit_read_key(read_key_buffer, timeout);
 #if ENABLE_PLATFORM_MINGW32
                 /* scroll to cursor position on any keypress */
@@ -2941,8 +2949,10 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
 
         /* restore initial_settings */
         tcsetattr_stdin_TCSANOW(&initial_settings);
+#if ENABLE_FEATURE_EDITING_WINCH
         /* restore SIGWINCH handler */
         sigaction_set(SIGWINCH, &S.SIGWINCH_handler);
+#endif
         fflush_all();
 
         len = command_len;