win32: enable globbing by default

Change how busybox.exe expands wildcards on the command line.

When globbing is enabled at compile time provide an implementation
of _setargv(), which is run early during startup of C programs.  This:

- enables globbing by setting _dowildcard to -1
- checks for the presence of the environment BB_GLOBBING
- if it exists and is set to 0 disables globbing
- if it doesn't exist sets BB_GLOBBING=0 but continues to apply
  Windows' globbing in the current process

The consequences of this are:

- When busybox.exe is initially run from a Command Prompt Windows'
  globbing is applied;
- Windows' globbing is turned off for future child processes, thus
  allowing the shell re-execute busybox.exe without it interfering
  with wildcards;
- this behaviour can be overridden by setting BB_GLOBBING explicitly.

Globbing can still be disabled at compile time if required.  In that
case BB_GLOBBING has no effect.

With these changes globbing can be enabled by default and BusyBox
will do the right thing in most circumstances.

(See GitHub issues #172 and #189.)

5 files changed, 26 insertions, 15 deletions

diff --git a/Config.in b/Config.in
index df8ecc3f0..d18f3dac5 100644
--- a/Config.in
+++ b/Config.in
@@ -387,15 +387,15 @@ comment 'Settings for MINGW32'
 
 config GLOBBING
         bool "Allow busybox.exe to expand wildcards"
-        default n
+        default y
         depends on PLATFORM_MINGW32
         help
           In Microsoft Windows expansion of wildcards on the command line
           ('globbing') is handled by the C runtime while the BusyBox shell
-          does its own wildcard expansion.  For best results when using the
-          shell globbing by the C runtime should be turned off. If you want
-          the BusyBox binary to handle wildcard expansion using the C runtime
-          set this to 'Y'.
+          does its own wildcard expansion. In most circumstances BusyBox
+          will do the right thing. If it doesn't or if you don't need to
+          use BusyBox applets from the Windows Command Prompt you can stop
+          busybox.exe from expanding wildcards by setting this to 'N'.
 
 choice
         prompt "Random number generator"
diff --git a/configs/mingw32_defconfig b/configs/mingw32_defconfig
index bffe88842..b3dfc0033 100644
--- a/configs/mingw32_defconfig
+++ b/configs/mingw32_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.32.0.git
-# Fri May 29 10:58:25 2020
+# Sun Jun 14 09:30:06 2020
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -43,7 +43,7 @@ CONFIG_BUSYBOX_EXEC_PATH=""
 #
 # Settings for MINGW32
 #
-# CONFIG_GLOBBING is not set
+CONFIG_GLOBBING=y
 CONFIG_FEATURE_PRNG_SHELL=y
 # CONFIG_FEATURE_PRNG_ISAAC is not set
 CONFIG_FEATURE_RESOURCES=y
diff --git a/configs/mingw64_defconfig b/configs/mingw64_defconfig
index d0a541162..2410d476d 100644
--- a/configs/mingw64_defconfig
+++ b/configs/mingw64_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.32.0.git
-# Fri May 29 10:59:57 2020
+# Sun Jun 14 09:30:06 2020
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -43,7 +43,7 @@ CONFIG_BUSYBOX_EXEC_PATH=""
 #
 # Settings for MINGW32
 #
-# CONFIG_GLOBBING is not set
+CONFIG_GLOBBING=y
 CONFIG_FEATURE_PRNG_SHELL=y
 # CONFIG_FEATURE_PRNG_ISAAC is not set
 CONFIG_FEATURE_RESOURCES=y
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 9caa04ac3..8c46d0d1b 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -915,11 +915,6 @@ int busybox_main(int argc UNUSED_PARAM, char **argv)
                         "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
                         )
                         "\n"
-#if ENABLE_GLOBBING
-                        "\tSupport for native Windows wildcards is enabled.  In some\n"
-                        "\tcases this may result in wildcards being processed twice.\n"
-                        "\n"
-#endif
                         "Currently defined functions:\n"
                 );
                 col = 0;
diff --git a/win32/mingw.c b/win32/mingw.c
index 105b7864d..06b22a2ed 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -10,7 +10,23 @@
 
 #if defined(__MINGW64_VERSION_MAJOR)
 #if ENABLE_GLOBBING
-int _dowildcard = -1;
+extern int _setargv(void);
+int _setargv(void)
+{
+        extern int _dowildcard;
+        char *glob;
+
+        _dowildcard = -1;
+        glob = getenv("BB_GLOBBING");
+        if (glob) {
+                if (strcmp(glob, "0") == 0)
+                        _dowildcard = 0;
+        }
+        else {
+                setenv("BB_GLOBBING", "0", TRUE);
+        }
+        return 0;
+}
 #else
 int _dowildcard = 0;
 #endif