mingw_spawnve(): transfer O_APPEND attribute to child processes

2 files changed, 69 insertions, 0 deletions

diff --git a/include/mingw.h b/include/mingw.h
index 762eb143a..eae6a7d3a 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -141,6 +141,15 @@ int link(const char *oldpath, const char *newpath);
 int mingw_open (const char *filename, int oflags, ...);
 #define open mingw_open
 
+int mingw_close (int fd);
+#define close mingw_close
+
+int mingw_dup (int fd);
+#define dup mingw_dup
+
+int mingw_dup2 (int fd, int fdto);
+#define dup2 mingw_dup2
+
 char *mingw_getcwd(char *pointer, int len);
 #define getcwd mingw_getcwd
 
diff --git a/libbb/mingw.c b/libbb/mingw.c
index 88d4f90e4..eb239bbd6 100644
--- a/libbb/mingw.c
+++ b/libbb/mingw.c
@@ -117,6 +117,14 @@ static int err_win_to_posix(DWORD winerr)
         return error;
 }
 
+/*
+ * emulate msvcrt file handle table
+ */
+#define MAX_FD 256
+#define WX_APPEND 0x20
+#define WX_OPEN 0x01
+static int fd_table[MAX_FD];
+
 #undef open
 int mingw_open (const char *filename, int oflags, ...)
 {
@@ -134,9 +142,41 @@ int mingw_open (const char *filename, int oflags, ...)
                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
                         errno = EISDIR;
         }
+        if (fd >= 0) {
+                fd_table[fd] = WX_OPEN;
+                if (oflags & O_APPEND)
+                        fd_table[fd] |= WX_APPEND;
+        }
         return fd;
 }
 
+#undef close
+int mingw_close (int fd)
+{
+        int ret = close(fd);
+        if (!ret)
+                fd_table[fd] = 0;
+        return ret;
+}
+
+#undef dup
+int mingw_dup (int fd)
+{
+        int ret = dup(fd);
+        if (ret != -1)
+                fd_table[ret] = fd_table[fd];
+        return ret;
+}
+
+#undef dup2
+int mingw_dup2 (int fd, int fdto)
+{
+        int ret = dup2(fd, fdto);
+        if (ret != -1)
+                fd_table[fdto] = fd_table[fd];
+        return ret;
+}
+
 static inline time_t filetime_to_time_t(const FILETIME *ft)
 {
         long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
@@ -649,6 +689,7 @@ static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
         struct strbuf envblk, args;
         unsigned flags;
         BOOL ret;
+        int i, fd_end;
 
         /* Determine whether or not we are associated to a console */
         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
@@ -682,6 +723,23 @@ static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
         si.hStdOutput = (HANDLE) _get_osfhandle(1);
         si.hStdError = (HANDLE) _get_osfhandle(2);
 
+        for (i = fd_end = 0;i < MAX_FD;i++)
+                if (fd_table[i] & WX_APPEND && fd_end <= i)
+                        fd_end = i+1;
+        if (fd_end > 0) {
+                char *attr;
+                HANDLE *handle;
+                si.cbReserved2 = sizeof(unsigned) + (sizeof(char)+sizeof(HANDLE))*fd_end;
+                si.lpReserved2 = xmalloc(si.cbReserved2);
+                *((unsigned*)si.lpReserved2) = fd_end;
+                attr = (char*)((unsigned*)si.lpReserved2+1);
+                handle = (HANDLE*)(attr+fd_end);
+                for (i = 0;i < fd_end;i++,handle++,attr++) {
+                        *attr = fd_table[i];
+                        *handle = fd_table[i] & WX_OPEN ? (HANDLE)_get_osfhandle(i) : INVALID_HANDLE_VALUE;
+                }
+        }
+
         /* concatenate argv, quoting args as we go */
         strbuf_init(&args, 0);
         if (prepend_cmd) {
@@ -723,6 +781,8 @@ static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
                 env ? envblk.buf : NULL, NULL, &si, &pi);
 
+        if (si.lpReserved2)
+                free(si.lpReserved2);
         if (env)
                 strbuf_release(&envblk);
         strbuf_release(&args);