win32: improved error for overlong command line

Report 'Arg list too long' rather than 'Invalid argument' when
spawnveq() detects that the EINVAL return from spawnve() is due to
the command line being too long.

Costs 48-64 bytes.

1 files changed, 6 insertions, 1 deletions

diff --git a/win32/process.c b/win32/process.c
index 5dc0f7080..5c818a3c0 100644
--- a/win32/process.c
+++ b/win32/process.c
@@ -189,6 +189,7 @@ spawnveq(int mode, const char *path, char *const *argv, char *const *env)
         int i, argc;
         intptr_t ret;
         struct stat st;
+        size_t len = 0;
 
         /*
          * Require that the file exists, is a regular file and is executable.
@@ -206,8 +207,10 @@ spawnveq(int mode, const char *path, char *const *argv, char *const *env)
 
         argc = string_array_len((char **)argv);
         new_argv = xzalloc(sizeof(*argv)*(argc+1));
-        for (i = 0;i < argc;i++)
+        for (i = 0; i < argc; i++) {
                 new_argv[i] = quote_arg(argv[i]);
+                len += strlen(new_argv[i]) + 1;
+        }
 
         /* Special case:  spawnve won't execute a batch file if the first
          * argument is a relative path containing forward slashes.  Absolute
@@ -234,6 +237,8 @@ spawnveq(int mode, const char *path, char *const *argv, char *const *env)
 
         errno = 0;
         ret = spawnve(mode, new_path ? new_path : path, new_argv, env);
+        if (errno == EINVAL && len > bb_arg_max())
+                errno = E2BIG;
 
  done:
         for (i = 0;i < argc;i++)