winansi: change default 'skip ANSI emulation' setting

Change the default 'skip ANSI emulation' setting which is used when
the environment variable BB_SKIP_ANSI_EMULATION is unset.  Previously
it was 0 (always emulate) now it's 2 (detect whether or not the
terminal supports ANSI escape sequences and behave accordingly).

The default value is also now a build-time option.

4 files changed, 24 insertions, 15 deletions

diff --git a/Config.in b/Config.in
index 2d1e9bc8b..6d91ad248 100644
--- a/Config.in
+++ b/Config.in
@@ -455,6 +455,23 @@ config FEATURE_EURO
         requires the OEM code page to be 858.  If the OEM code page of
         the console is 850 when BusyBox starts it's changed to 858.
 
+config SKIP_ANSI_EMULATION_DEFAULT
+        int "Default setting for ANSI escape sequences"
+        default 2
+        range 0 2
+        depends on PLATFORM_MINGW32
+        help
+        Control how ANSI escape sequences are handled.  Possible values
+        are:
+
+        0  Always emulate escape sequences.
+        1  Always emit escape sequences.
+        2  Emit escape sequences if the terminal supports them, otherwise
+           emulate them.
+
+        Setting the environment variable BB_SKIP_ANSI_EMULATION overrides
+        this default.
+
 config FEATURE_EXTRA_FILE_DATA
         bool "Read additional file metadata (2.1 kb)"
         default y
diff --git a/configs/mingw32_defconfig b/configs/mingw32_defconfig
index f95f71607..51b27f366 100644
--- a/configs/mingw32_defconfig
+++ b/configs/mingw32_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.34.0.git
-# Thu Jan 14 12:07:38 2021
+# Wed Feb  3 13:41:09 2021
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -52,6 +52,7 @@ CONFIG_FEATURE_ICON=y
 # CONFIG_FEATURE_ICON_STERM is not set
 CONFIG_FEATURE_ICON_ALL=y
 CONFIG_FEATURE_EURO=y
+CONFIG_SKIP_ANSI_EMULATION_DEFAULT=2
 CONFIG_FEATURE_EXTRA_FILE_DATA=y
 CONFIG_FEATURE_READLINK2=y
 
diff --git a/configs/mingw64_defconfig b/configs/mingw64_defconfig
index cf0e3ec8e..a8cb75215 100644
--- a/configs/mingw64_defconfig
+++ b/configs/mingw64_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.34.0.git
-# Thu Jan 14 12:07:38 2021
+# Wed Feb  3 13:41:09 2021
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -52,6 +52,7 @@ CONFIG_FEATURE_ICON=y
 # CONFIG_FEATURE_ICON_STERM is not set
 CONFIG_FEATURE_ICON_ALL=y
 CONFIG_FEATURE_EURO=y
+CONFIG_SKIP_ANSI_EMULATION_DEFAULT=2
 CONFIG_FEATURE_EXTRA_FILE_DATA=y
 CONFIG_FEATURE_READLINK2=y
 
diff --git a/win32/winansi.c b/win32/winansi.c
index 3767e7534..59292efc3 100644
--- a/win32/winansi.c
+++ b/win32/winansi.c
@@ -68,19 +68,9 @@ int skip_ansi_emulation(int reset)
 
         if (skip < 0 || reset) {
                 const char *var = getenv(bb_skip_ansi_emulation);
-                skip = var != NULL;
-                if (skip) {
-                        switch (xatou(var)) {
-                        case 1:
-                                break;
-                        case 2:
-                                skip = 2;
-                                break;
-                        default:
-                                skip = 0;
-                                break;
-                        }
-                }
+                skip = var == NULL ? CONFIG_SKIP_ANSI_EMULATION_DEFAULT : atoi(var);
+                if (skip < 0 || skip > 2)
+                        skip = 0;
 
                 if (is_console(STDOUT_FILENO)) {
                         HANDLE h = get_console();