Actually implement flags for gpgme_op_spawn.

* src/spawn.c (gpgme_op_spawn_start, gpgme_op_spawn): Pass FLAGS dow
to spawn_start and add FLAGS args along the call path.
* src/engine-spawn.c (engspawn_start): Hack to automagically provide
argv[0].

doc/gpgme.texi

@@ -5261,12 +5261,13 @@ with the GPGME API.
 
 The function @code{gpgme_op_spawn} runs the program @var{file} with
 the arguments taken from the NULL terminated array @var{argv}.  If no
-arguments are required @var{argv} may be given as @code{NULL} (in that
+arguments are required @var{argv} may be given as @code{NULL}.  In the
-case GPGME uses the basename of @var{file} for @code{argv[0]}).  The
+latter case or if @code{argv[0]} is the empty string, GPGME uses the
-file descriptors @code{stdin}, @code{stdout}, and @code{stderr} are
+basename of @var{file} for @code{argv[0]}.  The file descriptors
-connected to the data objects @var{datain}, @var{dataout}, and
+@code{stdin}, @code{stdout}, and @code{stderr} are connected to the
-@var{dataerr}.  If NULL is passed for one of these data objects the
+data objects @var{datain}, @var{dataout}, and @var{dataerr}.  If NULL
-corresponding file descriptor is connected to @file{/dev/null}.
+is passed for one of these data objects the corresponding file
+descriptor is connected to @file{/dev/null}.
 
 The value in @var{flags} is a bitwise-or combination of one or
 multiple of the following bit values:

src/engine-backend.h

@@ -130,7 +130,7 @@ struct engine_ops
                             const char *file, const char *argv[],
                             gpgme_data_t datain,
                             gpgme_data_t dataout,
-                            gpgme_data_t dataerr);
+                            gpgme_data_t dataerr, unsigned int flags);
 
 };
 

src/engine-spawn.c

@@ -231,6 +231,7 @@ engspawn_start (engine_spawn_t esp, const char *file, const char *argv[],
   struct spawn_fd_item_s *fd_list;
   pid_t pid;
   unsigned int spflags;
+  const char *save_argv0 = NULL;
 
   if (!esp || !file || !argv || !argv[0])
     return gpg_error (GPG_ERR_INV_VALUE);
@@ -264,8 +265,15 @@ engspawn_start (engine_spawn_t esp, const char *file, const char *argv[],
   fd_list[n].fd = -1;
   fd_list[n].dup_to = -1;
 
+  if (argv[0] && !*argv[0])
+    {
+      save_argv0 = argv[0];
+      argv[0] = _gpgme_get_basename (file);
+    }
   status = _gpgme_io_spawn (file, (char * const *)argv, spflags,
                             fd_list, NULL, NULL, &pid);
+  if (save_argv0)
+    argv[0] = save_argv0;
   free (fd_list);
   if (status == -1)
     return gpg_error_from_syserror ();

src/engine.c

@@ -944,7 +944,8 @@ gpgme_error_t
 _gpgme_engine_op_spawn (engine_t engine,
                         const char *file, const char *argv[],
                         gpgme_data_t datain,
-                        gpgme_data_t dataout, gpgme_data_t dataerr)
+                        gpgme_data_t dataout, gpgme_data_t dataerr,
+                        unsigned int flags)
 {
   if (!engine)
     return gpg_error (GPG_ERR_INV_VALUE);
@@ -953,5 +954,5 @@ _gpgme_engine_op_spawn (engine_t engine,
     return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
 
   return (*engine->ops->opspawn) (engine->engine, file, argv,
-                                  datain, dataout, dataerr);
+                                  datain, dataout, dataerr, flags);
 }

src/engine.h

@@ -167,7 +167,8 @@ gpgme_error_t _gpgme_engine_op_spawn (engine_t engine,
                                       const char *file, const char *argv[],
                                       gpgme_data_t datain,
                                       gpgme_data_t dataout,
-                                      gpgme_data_t dataerr);
+                                      gpgme_data_t dataerr,
+                                      unsigned int flags);
 
 
 #endif /* ENGINE_H */

src/spawn.c

@@ -34,7 +34,8 @@ static gpgme_error_t
 spawn_start (gpgme_ctx_t ctx, int synchronous,
              const char *file, const char *argv[],
              gpgme_data_t datain,
-             gpgme_data_t dataout, gpgme_data_t dataerr)
+             gpgme_data_t dataout, gpgme_data_t dataerr,
+             unsigned int flags)
 {
   gpgme_error_t err;
   const char *tmp_argv[2];
@@ -54,7 +55,7 @@ spawn_start (gpgme_ctx_t ctx, int synchronous,
     }
 
   return _gpgme_engine_op_spawn (ctx->engine, file, argv,
-                                 datain, dataout, dataerr);
+                                 datain, dataout, dataerr, flags);
 }
 
 
@@ -75,7 +76,7 @@ gpgme_op_spawn_start (gpgme_ctx_t ctx, const char *file, const char *argv[],
   if (!ctx)
     return TRACE_ERR (gpg_error (GPG_ERR_INV_VALUE));
 
-  err = spawn_start (ctx, 0, file, argv, datain, dataout, dataerr);
+  err = spawn_start (ctx, 0, file, argv, datain, dataout, dataerr, flags);
   return err;
 }
 
@@ -97,7 +98,7 @@ gpgme_op_spawn (gpgme_ctx_t ctx, const char *file, const char *argv[],
   if (!ctx)
     return TRACE_ERR (gpg_error (GPG_ERR_INV_VALUE));
 
-  err = spawn_start (ctx, 1, file, argv, datain, dataout, dataerr);
+  err = spawn_start (ctx, 1, file, argv, datain, dataout, dataerr, flags);
 
   if (!err)
     err = _gpgme_wait_one (ctx);