spawn plan apply: keep the plan's argv[0] — MRI does not re-prepend it (tebako#669)

patches/3.1/process_c_tebako_spawn.patch

@@ -53,7 +53,7 @@
 # exactly as before). A planned bare name (the app payload's
 # requires[].expose surface) retargets the exec pair to the store's
 # runtime exe, rebuilds argv_buf/argv_str from the plan (the plan's
-# argv[0] is the exe; ruby re-prepends it at exec), and applies the
+# argv[0] rides as the child's own argv[0] at exec), and applies the
 # plan's env ops (KEY=VALUE sets, bare KEY deletes) into
 # env_modification. A named error raises — the spawn NEVER falls through
 # to a host binary of the same name. The head runs BEFORE the darwin
@@ -69,7 +69,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -172,11 +172,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -189,7 +188,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/3.2/process_c_tebako_spawn.patch

@@ -53,7 +53,7 @@
 # exactly as before). A planned bare name (the app payload's
 # requires[].expose surface) retargets the exec pair to the store's
 # runtime exe, rebuilds argv_buf/argv_str from the plan (the plan's
-# argv[0] is the exe; ruby re-prepends it at exec), and applies the
+# argv[0] rides as the child's own argv[0] at exec), and applies the
 # plan's env ops (KEY=VALUE sets, bare KEY deletes) into
 # env_modification. A named error raises — the spawn NEVER falls through
 # to a host binary of the same name. The head runs BEFORE the darwin
@@ -69,7 +69,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -172,11 +172,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -189,7 +188,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/3.2/process_c_tebako_spawn_msys.patch

@@ -22,7 +22,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -125,11 +125,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -142,7 +141,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/3.3/process_c_tebako_spawn.patch

@@ -53,7 +53,7 @@
 # exactly as before). A planned bare name (the app payload's
 # requires[].expose surface) retargets the exec pair to the store's
 # runtime exe, rebuilds argv_buf/argv_str from the plan (the plan's
-# argv[0] is the exe; ruby re-prepends it at exec), and applies the
+# argv[0] rides as the child's own argv[0] at exec), and applies the
 # plan's env ops (KEY=VALUE sets, bare KEY deletes) into
 # env_modification. A named error raises — the spawn NEVER falls through
 # to a host binary of the same name. The head runs BEFORE the darwin
@@ -69,7 +69,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -172,11 +172,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -189,7 +188,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/3.3/process_c_tebako_spawn_msys.patch

@@ -22,7 +22,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -125,11 +125,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -142,7 +141,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/3.4/process_c_tebako_spawn.patch

@@ -53,7 +53,7 @@
 # exactly as before). A planned bare name (the app payload's
 # requires[].expose surface) retargets the exec pair to the store's
 # runtime exe, rebuilds argv_buf/argv_str from the plan (the plan's
-# argv[0] is the exe; ruby re-prepends it at exec), and applies the
+# argv[0] rides as the child's own argv[0] at exec), and applies the
 # plan's env ops (KEY=VALUE sets, bare KEY deletes) into
 # env_modification. A named error raises — the spawn NEVER falls through
 # to a host binary of the same name. The head runs BEFORE the darwin
@@ -69,7 +69,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -172,11 +172,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -189,7 +188,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/3.4/process_c_tebako_spawn_msys.patch

@@ -22,7 +22,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,854 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,852 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -125,11 +125,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -142,7 +141,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);

patches/4.0/process_c_tebako_spawn.patch

@@ -59,7 +59,7 @@
 # exactly as before). A planned bare name (the app payload's
 # requires[].expose surface) retargets the exec pair to the store's
 # runtime exe, rebuilds argv_buf/argv_str from the plan (the plan's
-# argv[0] is the exe; ruby re-prepends it at exec), and applies the
+# argv[0] rides as the child's own argv[0] at exec), and applies the
 # plan's env ops (KEY=VALUE sets, bare KEY deletes) into
 # env_modification. A named error raises — the spawn NEVER falls through
 # to a host binary of the same name. The head runs BEFORE the darwin
@@ -75,7 +75,7 @@ diff --git a/process.c b/process.c
 index 97fa336..f55697e 100644
 --- a/process.c
 +++ b/process.c
-@@ -2834,6 +2834,858 @@ rb_execarg_get(VALUE execarg_obj)
+@@ -2834,6 +2834,856 @@ rb_execarg_get(VALUE execarg_obj)
      return eargp;
  }
 
@@ -178,11 +178,10 @@ index 97fa336..f55697e 100644
 +}
 +
 +/* A planned spawn (spec 30 §2): the plan's exe becomes the exec pair;
-+   argv_buf takes the plan's tokens AFTER argv[0] (ruby re-prepends the
-+   program at exec from command_abspath — and the plan's argv[0] IS that
-+   exe); argv_str's pointer vector is rebuilt into the new buffer exactly
-+   as rb_exec_fillarg built it (the vector points INTO the buffer's
-+   storage, so a new buffer means a rebuilt vector). */
++   argv_buf takes the plan's FULL argv, argv[0] included — the exec file
++   comes from command_abspath while the child's argv[0] is argv_buf's
++   first token (rb_exec_fillarg's exact layout); argv_str's pointers
++   point INTO the buffer, so a new buffer means a rebuilt vector. */
 +static void
 +tfs_spawn_plan_apply(struct rb_execarg *eargp, const char *exe,
 +                     const char *argv, size_t argv_len,
@@ -195,7 +194,6 @@ index 97fa336..f55697e 100644
 +    VALUE av;
 +    eargp->invoke.cmd.command_name = rb_str_new_cstr(exe);
 +    eargp->invoke.cmd.command_abspath = rb_str_new_cstr(exe);
-+    if (p < ep) p += strlen(p) + 1;  /* the plan's argv[0] is the exe */
 +    nbuf = hide_obj(rb_str_buf_new((ep - p) + 1));
 +    while (p < ep) {
 +        rb_str_buf_cat(nbuf, p, strlen(p) + 1);