1 files changed, 34 insertions, 4 deletions
diff --git a/compat/mingw.h b/compat/mingw.h
index 4c14e30835..8c24ddaa3e 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -11,6 +11,9 @@ typedef _sigset_t sigset_t;
 #undef _POSIX_THREAD_SAFE_FUNCTIONS
 #endif
 
+extern int mingw_core_config(const char *var, const char *value, void *cb);
+#define platform_core_config mingw_core_config
+
 /*
  * things that are not available in header files
  */
@@ -257,11 +260,35 @@ char *mingw_mktemp(char *template);
 char *mingw_getcwd(char *pointer, int len);
 #define getcwd mingw_getcwd
 
+#ifdef NO_UNSETENV
+#error "NO_UNSETENV is incompatible with the Windows-specific startup code!"
+#endif
+
+/*
+ * We bind *env() routines (even the mingw_ ones) to private mingw_ versions.
+ * These talk to the CRT using UNICODE/wchar_t, but maintain the original
+ * narrow-char API.
+ *
+ * Note that the MSCRT maintains both ANSI (getenv()) and UNICODE (_wgetenv())
+ * routines and stores both versions of each environment variable in parallel
+ * (and secretly updates both when you set one or the other), but it uses CP_ACP
+ * to do the conversion rather than CP_UTF8.
+ *
+ * Since everything in the git code base is UTF8, we define the mingw_ routines
+ * to access the CRT using the UNICODE routines and manually convert them to
+ * UTF8.  This also avoids round-trip problems.
+ *
+ * This also helps with our linkage, since "_wenviron" is publicly exported
+ * from the CRT.  But to access "_environ" we would have to statically link
+ * to the CRT (/MT).
+ *
+ * We require NO_SETENV (and let gitsetenv() call our mingw_putenv).
+ */
+#define getenv       mingw_getenv
+#define putenv       mingw_putenv
+#define unsetenv     mingw_putenv
 char *mingw_getenv(const char *name);
-#define getenv mingw_getenv
-int mingw_putenv(const char *namevalue);
-#define putenv mingw_putenv
-#define unsetenv mingw_putenv
+int   mingw_putenv(const char *name);
 
 int mingw_gethostname(char *host, int namelen);
 #define gethostname mingw_gethostname
@@ -406,6 +433,9 @@ int mingw_raise(int sig);
 int winansi_isatty(int fd);
 #define isatty winansi_isatty
 
+int winansi_dup2(int oldfd, int newfd);
+#define dup2 winansi_dup2
+
 void winansi_init(void);
 HANDLE winansi_get_osfhandle(int fd);