* eval.c (rb_f_require): searches ".rb" and ".so" at the same

  time.  previous behavior (search ".rb", then ".so") has a
  security risk (ruby-bugs#PR140).

* array.c (rb_ary_to_ary): new function to replace internal
  rb_Array(), which never calls to_a, but to_ary (rb_Array() might
  call both). [new]

* regex.c (PUSH_FAILURE_POINT): push option status again.

* regex.c (re_compile_pattern): avoid pushing unnecessary
  option_set.

* eval.c (rb_load): tainted string is OK if wrapped *and*
  $SAFE >= 4.

* eval.c (rb_thread_start_0): should not nail down higher blocks
  before preserving original context (i.e. should not alter
  original context).

* eval.c (proc_yield): new method equivalent to Proc#call but no
  check for number of arguments. [new]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1526 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

10 files changed, 249 insertions, 104 deletions

diff --git a/ChangeLog b/ChangeLog
index 748eaf6995..548fad86d8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,9 +1,42 @@
+Mon Jun 18 17:38:50 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (rb_f_require): searches ".rb" and ".so" at the same
+	  time.  previous behavior (search ".rb", then ".so") has a
+	  security risk (ruby-bugs#PR140).
+
+	* array.c (rb_ary_to_ary): new function to replace internal
+	  rb_Array(), which never calls to_a, but to_ary (rb_Array() might
+	  call both). [new]
+
+Mon Jun 18 00:43:20 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* regex.c (PUSH_FAILURE_POINT): push option status again.
+
+	* regex.c (re_compile_pattern): avoid pushing unnecessary
+	  option_set.
+
+Sat Jun 16 10:58:48 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (rb_load): tainted string is OK if wrapped *and*
+	  $SAFE >= 4.
+
+Thu Jun 14 16:27:07 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (rb_thread_start_0): should not nail down higher blocks
+	  before preserving original context (i.e. should not alter
+	  original context).
+
 Wed Jun 13 19:34:59 2001  Akinori MUSHA  <knu@iDaemons.org>
 
 	* dir.c (Init_Dir): add a new method File::fnmatch? along with
 	  File::Constants::FNM_*.  While I am here, FNM_NOCASE is renamed
 	  to FNM_CASEFOLD which is commonly used by *BSD and GNU libc.
 
+Wed Jun 13 09:33:45 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (proc_yield): new method equivalent to Proc#call but no
+	  check for number of arguments. [new]
+
 Tue Jun 12 14:21:28 2001  Nobuyoshi Nakada  <nobu.nakada@nifty.ne.jp>
 
 	* lib/mkmf.rb: target_prefix is only for installation, not for
diff --git a/ToDo b/ToDo
index 7a22319bef..e9d0d74adf 100644
--- a/ToDo
+++ b/ToDo
@@ -83,6 +83,7 @@ Standard Libraries
 * hash etc. should handle self referenceing array/hash
 * move NameError under StandardError.
 * library to load per-user profile seeking .ruby_profile or ruby.ini file.
+* warning framework
 
 Extension Libraries
 
diff --git a/array.c b/array.c
index 010afd9a39..d0f6977a13 100644
--- a/array.c
+++ b/array.c
@@ -17,6 +17,7 @@
 #include "st.h"
 
 VALUE rb_cArray;
+static ID cmp;
 
 #define ARY_DEFAULT_SIZE 16
 
@@ -729,6 +730,20 @@ to_ary(ary)
     return rb_convert_type(ary, T_ARRAY, "Array", "to_ary");
 }
 
+VALUE
+rb_ary_to_ary(obj)
+    VALUE obj;
+{
+    if (NIL_P(obj)) return rb_ary_new2(0);
+    if (TYPE(obj) == T_ARRAY) {
+	return obj;
+    }
+    if (rb_respond_to(obj, rb_intern("to_ary"))) {
+	return rb_convert_type(obj, T_ARRAY, "Array", "to_ary");
+    }
+    return rb_ary_new3(1, obj);
+}
+
 extern VALUE rb_output_fs;
 
 static VALUE
@@ -958,8 +973,6 @@ rb_ary_reverse_m(ary)
     return rb_ary_reverse(rb_obj_dup(ary));
 }
 
-static ID cmp;
-
 static int
 sort_1(a, b)
     VALUE *a, *b;
diff --git a/eval.c b/eval.c
index 80905ba8af..314744b0ac 100644
--- a/eval.c
+++ b/eval.c
@@ -1676,7 +1676,7 @@ copy_node_scope(node, rval)
 	char *file = ruby_sourcefile;\
 	int line = ruby_sourceline;\
 	if (TYPE(args) != T_ARRAY)\
-	    args = rb_Array(args);\
+	    args = rb_ary_to_ary(args);\
         argc = RARRAY(args)->len;\
 	argv = ALLOCA_N(VALUE, argc);\
 	MEMCPY(argv, RARRAY(args)->ptr, VALUE, argc);\
@@ -2129,7 +2129,7 @@ rb_eval(self, n)
 		    VALUE v = rb_eval(self, tag->nd_head->nd_head);
 		    int i;
 
-		    if (TYPE(v) != T_ARRAY) v = rb_Array(v);
+		    if (TYPE(v) != T_ARRAY) v = rb_ary_to_ary(v);
 		    for (i=0; i<RARRAY(v)->len; i++) {
 			if (RTEST(RARRAY(v)->ptr[i])) {
 			    node = node->nd_body;
@@ -2174,7 +2174,7 @@ rb_eval(self, n)
 			VALUE v = rb_eval(self, tag->nd_head->nd_head);
 			int i;
 
-			if (TYPE(v) != T_ARRAY) v = rb_Array(v);
+			if (TYPE(v) != T_ARRAY) v = rb_ary_to_ary(v);
 			for (i=0; i<RARRAY(v)->len; i++) {
 			    if (RTEST(rb_funcall2(RARRAY(v)->ptr[i], eqq, 1, &val))){
 				node = node->nd_body;
@@ -2347,14 +2347,14 @@ rb_eval(self, n)
       case NODE_RESTARY:
 	result = rb_eval(self, node->nd_head);
 	if (TYPE(result) != T_ARRAY) {
-	    result = rb_Array(result);
+	    result = rb_ary_to_ary(result);
 	}
 	break;
 
       case NODE_REXPAND:
 	result = rb_eval(self, node->nd_head);
 	if (TYPE(result) != T_ARRAY) {
-	    result = rb_Array(result);
+	    result = rb_ary_to_ary(result);
 	}
 	if (RARRAY(result)->len == 0) {
 	    result = Qnil;
@@ -2520,7 +2520,7 @@ rb_eval(self, n)
 
       case NODE_ARGSCAT:
 	result = rb_ary_concat(rb_eval(self, node->nd_head),
-			       rb_Array(rb_eval(self, node->nd_body)));
+			       rb_ary_to_ary(rb_eval(self, node->nd_body)));
 	break;
 
       case NODE_ARGSPUSH:
@@ -3546,16 +3546,20 @@ rb_f_block_given_p()
     return Qfalse;
 }
 
+#define PC_NONE   0x0
+#define PC_ACHECK 0x1
+#define PC_PCALL  0x2
+
 static VALUE
-rb_yield_0(val, self, klass, acheck)
+rb_yield_0(val, self, klass, pcall)
     VALUE val, self, klass;	/* OK */
-    int acheck;
+    int pcall;
 {
     NODE *node;
     volatile VALUE result = Qnil;
     volatile VALUE old_cref;
-    struct BLOCK *block;
-    struct SCOPE *old_scope;
+    struct BLOCK * volatile block;
+    struct SCOPE * volatile old_scope;
     struct FRAME frame;
     int state;
     static unsigned serial = 1;
@@ -3591,7 +3595,7 @@ rb_yield_0(val, self, klass, acheck)
 	PUSH_TAG(PROT_NONE);
 	if ((state = EXEC_TAG()) == 0) {
 	    if (block->var == (NODE*)1) {
-		if (acheck && val != Qundef &&
+		if ((pcall&PC_ACHECK) && val != Qundef &&
 		    TYPE(val) == T_ARRAY && RARRAY(val)->len != 0) {
 		    rb_raise(rb_eArgError, "wrong # of arguments (%d for 0)",
 			     RARRAY(val)->len);
@@ -3605,14 +3609,14 @@ rb_yield_0(val, self, klass, acheck)
 	    }
 	    else {
 		if (nd_type(block->var) == NODE_MASGN)
-		    massign(self, block->var, val, acheck);
+		    massign(self, block->var, val, (pcall&PC_ACHECK));
 		else {
 		    /* argument adjust for proc_call etc. */
-		    if (acheck && val != Qundef && 
+		    if (pcall && val != Qundef && 
 			TYPE(val) == T_ARRAY && RARRAY(val)->len == 1) {
 			val = RARRAY(val)->ptr[0];
 		    }
-		    assign(self, block->var, val, acheck);
+		    assign(self, block->var, val, (pcall&PC_ACHECK));
 		}
 	    }
 	}
@@ -3621,7 +3625,7 @@ rb_yield_0(val, self, klass, acheck)
     }
     else {
 	/* argument adjust for proc_call etc. */
-	if (acheck && val != Qundef &&
+	if (pcall && val != Qundef &&
 	    TYPE(val) == T_ARRAY && RARRAY(val)->len == 1) {
 	    val = RARRAY(val)->ptr[0];
 	}
@@ -5171,7 +5175,12 @@ rb_load(fname, wrap)
     NODE *saved_cref = ruby_cref;
     TMP_PROTECT;
 
-    SafeStringValue(fname);
+    if (wrap && ruby_safe_level >= 4) {
+	StringValue(fname);
+    }
+    else {
+	SafeStringValue(fname);
+    }
     file = rb_find_file(RSTRING(fname)->ptr);
     if (!file) {
 	rb_raise(rb_eLoadError, "No such file to load -- %s", RSTRING(fname)->ptr);
@@ -5402,28 +5411,20 @@ rb_f_require(obj, fname)
     }
     buf = ALLOCA_N(char, strlen(RSTRING(fname)->ptr) + 5);
     strcpy(buf, RSTRING(fname)->ptr);
-    strcat(buf, ".rb");
-    if (rb_find_file(buf)) {
+    switch (rb_find_file_noext(buf)) {
+      case 0:
+	break;
+
+      case 1:
 	fname = rb_str_new2(buf);
-	feature = buf;
+	file = feature = buf;
 	goto load_rb;
-    }
-    strcpy(buf, RSTRING(fname)->ptr);
-    strcat(buf, DLEXT);
-    file = rb_find_file(buf);
-    if (file) {
-	feature = buf;
-	goto load_dyna;
-    }
-#ifdef DLEXT2
-    strcpy(buf, RSTRING(fname)->ptr);
-    strcat(buf, DLEXT2);
-    file = rb_find_file(buf);
-    if (file) {
+
+      default:
 	feature = buf;
+	file = rb_find_file(buf);
 	goto load_dyna;
     }
-#endif
     rb_raise(rb_eLoadError, "No such file to load -- %s",
 	     RSTRING(fname)->ptr);
 
@@ -6330,8 +6331,9 @@ callargs(args)
 }
 
 static VALUE
-proc_call(proc, args)
+proc_invoke(proc, args, pcall)
     VALUE proc, args;		/* OK */
+    int pcall;
 {
     struct BLOCK * volatile old_block;
     struct BLOCK _block;
@@ -6341,6 +6343,13 @@ proc_call(proc, args)
     volatile int orphan;
     volatile int safe = ruby_safe_level;
 
+    if (pcall) {
+	pcall = PC_ACHECK|PC_PCALL;
+    }
+    else {
+	pcall = PC_PCALL;
+    }
+
     if (rb_block_given_p() && ruby_frame->last_func) {
 	rb_warning("block for %s#%s is useless",
 		   rb_class2name(CLASS_OF(proc)),
@@ -6367,7 +6376,7 @@ proc_call(proc, args)
     state = EXEC_TAG();
     if (state == 0) {
 	proc_set_safe_level(proc);
-	result = rb_yield_0(args, 0, 0, Qtrue);
+	result = rb_yield_0(args, 0, 0, pcall);
     }
     POP_TAG();
 
@@ -6399,6 +6408,20 @@ proc_call(proc, args)
 }
 
 static VALUE
+proc_call(proc, args)
+    VALUE proc, args;		/* OK */
+{
+    return proc_invoke(proc, args, Qtrue);
+}
+
+static VALUE
+proc_yield(proc, args)
+    VALUE proc, args;		/* OK */
+{
+    return proc_invoke(proc, args, Qfalse);
+}
+
+static VALUE
 proc_arity(proc)
     VALUE proc;
 {
@@ -6899,6 +6922,7 @@ Init_Proc()
     rb_define_singleton_method(rb_cProc, "new", proc_s_new, -1);
 
     rb_define_method(rb_cProc, "call", proc_call, -2);
+    rb_define_method(rb_cProc, "yield", proc_yield, -2);
     rb_define_method(rb_cProc, "arity", proc_arity, 0);
     rb_define_method(rb_cProc, "[]", proc_call, -2);
     rb_define_method(rb_cProc, "==", proc_eq, 1);
@@ -8210,7 +8234,11 @@ rb_thread_start_0(fn, arg, th_arg)
     }
 #endif
 
-    if (ruby_block) {		/* should nail down higher scopes */
+    if (THREAD_SAVE_CONTEXT(curr_thread)) {
+	return thread;
+    }
+
+    if (ruby_block) {		/* should nail down higher blocks */
 	struct BLOCK dummy;
 
 	dummy.prev = ruby_block;
@@ -8219,9 +8247,6 @@ rb_thread_start_0(fn, arg, th_arg)
     }
     scope_dup(ruby_scope);
     FL_SET(ruby_scope, SCOPE_SHARED);
-    if (THREAD_SAVE_CONTEXT(curr_thread)) {
-	return thread;
-    }
 
     if (!th->next) {
 	/* merge in thread list */
@@ -8243,17 +8268,21 @@ rb_thread_start_0(fn, arg, th_arg)
     POP_TAG();
     status = th->status;
 
+    if (th == main_thread) ruby_stop(state);
+    rb_thread_remove(th);
+
     while (saved_block) {
 	struct BLOCK *tmp = saved_block;
 
+	if (curr_thread == main_thread) {
+	    printf("free(%p)\n", saved_block);
+	}
 	if (tmp->frame.argc > 0)
 	    free(tmp->frame.argv);
 	saved_block = tmp->prev;
 	free(tmp);
     }
 
-    if (th == main_thread) ruby_stop(state);
-    rb_thread_remove(th);
     if (state && status != THREAD_TO_KILL && !NIL_P(ruby_errinfo)) {
 	th->flags |= THREAD_RAISED;
 	if (state == TAG_FATAL) { 
diff --git a/file.c b/file.c
index 1cff4778ca..66f82bcc58 100644
--- a/file.c
+++ b/file.c
@@ -2202,48 +2202,99 @@ is_macos_native_path(path)
 }
 #endif
 
+static char*
+file_load_ok(file)
+    char *file;
+{
+    FILE *f;
+
+    f = fopen(file, "r");
+    if (f == NULL) return 0;
+    fclose(f);
+    return file;
+}
+
+extern VALUE rb_load_path;
+
+int
+rb_find_file_noext(file)
+    char *file;
+{
+    char *path, *e, *found;
+    char *fend = file + strlen(file);
+    VALUE fname;
+    int i, j;
+
+    static char *ext[] = {
+	".rb", DLEXT,
+#ifdef DLEXT2
+	DLEXT2,
+#endif
+	0
+    };
+
+    if (file[0] == '~') {
+	fname = rb_str_new2(file);
+	fname = rb_file_s_expand_path(1, &fname);
+	file = StringValuePtr(fname);
+    }
+
+    if (is_absolute_path(file)) {
+	for (i=0; ext[i]; i++) {
+	    strcpy(fend, ext[i]);
+	    if (file_load_ok(file)) return i+1;
+	}
+	return 0;
+    }
+
+    if (!rb_load_path) return 0;
+
+    Check_Type(rb_load_path, T_ARRAY);
+    for (i=0;i<RARRAY(rb_load_path)->len;i++) {
+	VALUE str = RARRAY(rb_load_path)->ptr[i];
+
+	SafeStringValue(str);
+	path = RSTRING(str)->ptr;
+	for (j=0; ext[j]; j++) {
+	    strcpy(fend, ext[j]);
+	    found = dln_find_file(file, path);
+	    if (found && file_load_ok(found)) return j+1;
+	}
+    }
+    return 0;
+}
+
 char*
 rb_find_file(file)
     char *file;
 {
-    extern VALUE rb_load_path;
     VALUE vpath, fname;
     char *path;
     struct stat st;
 
+    if (file[0] == '~') {
+	fname = rb_str_new2(file);
+	fname = rb_file_s_expand_path(1, &fname);
+	if (rb_safe_level() >= 2 && OBJ_TAINTED(fname)) {
+	    rb_raise(rb_eSecurityError, "loading from unsafe file %s", file);
+	}
+	file = StringValuePtr(fname);
+    }
+
 #if defined(__MACOS__) || defined(riscos)
     if (is_macos_native_path(file)) {
-	FILE *f;
-
 	if (rb_safe_level() >= 2 && !rb_path_check(file)) {
 	    rb_raise(rb_eSecurityError, "loading from unsafe file %s", file);
 	}
-	f= fopen(file, "r");
-	if (f == NULL) return 0;
-	fclose(f);
-	return file;
+	return file_load_ok(file);
     }
 #endif
 
     if (is_absolute_path(file)) {
-	FILE *f;
-
 	if (rb_safe_level() >= 2 && !rb_path_check(file)) {
 	    rb_raise(rb_eSecurityError, "loading from unsafe file %s", file);
 	}
-	f = fopen(file, "r");
-	if (f == NULL) return 0;
-	fclose(f);
-	return file;
-    }
-
-    if (file[0] == '~') {
-	fname = rb_str_new2(file);
-	fname = rb_file_s_expand_path(1, &fname);
-	if (rb_safe_level() >= 2 && OBJ_TAINTED(fname)) {
-	    rb_raise(rb_eSecurityError, "loading from unsafe file %s", file);
-	}
-	file = StringValuePtr(fname);
+	return file_load_ok(file);
     }
 
     if (rb_load_path) {
@@ -2269,10 +2320,7 @@ rb_find_file(file)
     }
 
     path = dln_find_file(file, path);
-    if (path && stat(path, &st) == 0) {
-	return path;
-    }
-    return 0;
+    return file_load_ok(path);
 }
 
 static void
diff --git a/intern.h b/intern.h
index 866df5845d..ebfc57cffc 100644
--- a/intern.h
+++ b/intern.h
@@ -27,6 +27,7 @@ VALUE rb_ary_new4 _((long, VALUE *));
 VALUE rb_ary_freeze _((VALUE));
 VALUE rb_ary_aref _((int, VALUE*, VALUE));
 void rb_ary_store _((VALUE, long, VALUE));
+VALUE rb_ary_to_ary _((VALUE));
 VALUE rb_ary_to_s _((VALUE));
 VALUE rb_ary_push _((VALUE, VALUE));
 VALUE rb_ary_pop _((VALUE));
@@ -179,6 +180,7 @@ void rb_thread_atfork _((void));
 int eaccess _((const char*, int));
 VALUE rb_file_s_expand_path _((int, VALUE *));
 void rb_file_const _((const char*, VALUE));
+int rb_find_file_noext _((char*));
 char *rb_find_file _((char*));
 /* gc.c */
 void rb_gc_mark_locations _((VALUE*, VALUE*));
diff --git a/io.c b/io.c
index 3bcf663aad..ae021f8a4b 100644
--- a/io.c
+++ b/io.c
@@ -3462,10 +3462,8 @@ opt_i_set(val)
     VALUE val;
 {
     if (ruby_inplace_mode) free(ruby_inplace_mode);
-    if (!RTEST(val)) {
-	ruby_inplace_mode = 0;
-	return;
-    }
+    ruby_inplace_mode = 0;
+    if (!RTEST(val)) return;
     StringValue(val);
     ruby_inplace_mode = strdup(RSTRING(val)->ptr);
 }
diff --git a/lib/resolv.rb b/lib/resolv.rb
index 782501b7cc..16cf4b5c88 100644
--- a/lib/resolv.rb
+++ b/lib/resolv.rb
@@ -854,7 +854,7 @@ class Resolv
           raise DecodeError.new("limit exceed") if @limit < @index + len
           arr = @data.unpack("@#{@index}#{template}")
           @index += len
-          return *arr
+          return arr
         end
 
         def get_string
diff --git a/misc/ruby-mode.el b/misc/ruby-mode.el
index 102de81b5a..da31f989d1 100644
--- a/misc/ruby-mode.el
+++ b/misc/ruby-mode.el
@@ -660,21 +660,24 @@ An end of a defun is found by moving forward from the beginning of one."
 
 (cond
  ((featurep 'font-lock)
-
-  (setq ruby-font-lock-syntactic-keywords
- 	'(("\\$\\([#\"'`$\\]\\)" 1 (1 . nil))
- 	  ("\\(#\\)[{$@]" 1 (1 . nil))
- 	  ("\\(/\\)\\([^/\n]\\|\\/\\)*\\(/\\)"
- 	   (1 (7 . ?'))
- 	   (3 (7 . ?')))
-	  ("^\\(=\\)begin\\(\\s \\|$\\)" 1 (7 . nil))
-	  ("^\\(=\\)end\\(\\s \\|$\\)" 1 (7 . nil))))
-  (put major-mode 'font-lock-defaults
-       '((ruby-font-lock-keywords)
-	 nil nil nil
-	 beginning-of-line
-	 (font-lock-syntactic-keywords
-	  . ruby-font-lock-syntactic-keywords)))
+  (or (boundp 'font-lock-variable-name-face)
+      (setq font-lock-variable-name-face font-lock-type-face))
+
+
+  (add-hook 'ruby-mode-hook
+	    '(lambda ()
+	       (make-local-variable 'font-lock-syntactic-keywords)
+	       (setq font-lock-syntactic-keywords
+		     '(("\\$\\([#\"'`$\\]\\)" 1 (1 . nil))
+		       ("\\(#\\)[{$@]" 1 (1 . nil))
+		       ("\\(/\\)\\([^/\n]\\|\\/\\)*\\(/\\)"
+			(1 (7 . ?'))
+			(3 (7 . ?')))
+		       ("^\\(=\\)begin\\(\\s \\|$\\)" 1 (7 . nil))
+		       ("^\\(=\\)end\\(\\s \\|$\\)" 1 (7 . nil))))
+	       (make-local-variable 'font-lock-defaults)
+	       (setq font-lock-defaults '((ruby-font-lock-keywords) nil nil))
+	       (setq font-lock-keywords ruby-font-lock-keywords)))
 
   (defun ruby-font-lock-docs (limit)
     (if (re-search-forward "^=begin\\(\\s \\|$\\)" limit t)
@@ -687,6 +690,21 @@ An end of a defun is found by moving forward from the beginning of one."
 		(set-match-data (list beg (point)))
 		t)))))
 
+  (defun ruby-font-lock-maybe-docs (limit)
+    (let (beg)
+      (save-excursion
+	(if (and (re-search-backward "^=\\(begin\\|end\\)\\(\\s \\|$\\)" nil t)
+		 (string= (match-string-no-properties 1) "begin"))
+	    (progn
+	      (beginning-of-line)
+	      (setq beg (point)))))
+      (if (and beg (and (re-search-forward "^=\\(begin\\|end\\)\\(\\s \\|$\\)" nil t)
+			(string= (match-string-no-properties 1) "end")))
+	  (progn
+	    (set-match-data (list beg (point)))
+	    t)
+	nil)))
+
   (defvar ruby-font-lock-keywords
     (list
      (cons (concat
@@ -741,6 +759,8 @@ An end of a defun is found by moving forward from the beginning of one."
      ;; embedded document
      '(ruby-font-lock-docs
        0 font-lock-comment-face t)
+     '(ruby-font-lock-maybe-docs
+       0 font-lock-comment-face t)
      ;; constants
      '("\\(^\\|[^_]\\)\\b\\([A-Z]+\\(\\w\\|_\\)*\\)"
        2 font-lock-type-face)
diff --git a/regex.c b/regex.c
index 39e65da9b9..e40c0e4ff2 100644
--- a/regex.c
+++ b/regex.c
@@ -1874,8 +1874,10 @@ re_compile_pattern(pattern, size, bufp)
 	if ((options ^ stackp[-1]) & RE_OPTION_IGNORECASE) {
 	  BUFPUSH((options&RE_OPTION_IGNORECASE)?casefold_off:casefold_on);
 	}
-	BUFPUSH(option_set);
-	BUFPUSH(stackp[-1]);
+	if ((options ^ stackp[-1]) != RE_OPTION_IGNORECASE) {
+	  BUFPUSH(option_set);
+	  BUFPUSH(stackp[-1]);
+	}
       }
       p0 = b;
       options = *--stackp;
@@ -3262,7 +3264,8 @@ re_search(bufp, string, size, startpos, range, regs)
     }
 
     if (startpos > size) return -1;
-    if (anchor && size > 0 && startpos == size) return -1;
+    if ((anchor || !bufp->can_be_null) && size > 0 && startpos == size)
+      return -1;
     val = re_match(bufp, string, size, startpos, regs);
     if (val >= 0) return startpos;
     if (val == -2) return -2;
@@ -3362,7 +3365,7 @@ re_search(bufp, string, size, startpos, range, regs)
 #define NUM_COUNT_ITEMS 2
 
 /* Individual items aside from the registers.  */
-#define NUM_NONREG_ITEMS 3
+#define NUM_NONREG_ITEMS 4
 
 /* We push at most this many things on the stack whenever we
    fail.  The `+ 2' refers to PATTERN_PLACE and STRING_PLACE, which are
@@ -3412,6 +3415,7 @@ re_search(bufp, string, size, startpos, range, regs)
 									\
     *stackp++ = pattern_place;                                          \
     *stackp++ = string_place;                                           \
+    *stackp++ = (unsigned char*)options; /* current option status */	\
     *stackp++ = (unsigned char*)0; /* non-greedy flag */		\
   } while(0)
 
@@ -3735,15 +3739,11 @@ re_match(bufp, string_arg, size, pos, regs)
 	  int regno = *p++;   /* Get which register to match against */
 	  register unsigned char *d2, *dend2;
 
-#if 0
 	  /* Check if corresponding group is still open */
 	  if (IS_ACTIVE(reg_info[regno])) goto fail;
 
 	  /* Where in input to try to start matching.  */
 	  d2 = regstart[regno];
-#else
-          d2 = IS_ACTIVE(reg_info[regno])?old_regstart[regno]:regstart[regno];
-#endif
 	  if (REG_UNSET(d2)) goto fail;
 
 	  /* Where to stop matching; if both the place to start and
@@ -3791,7 +3791,7 @@ re_match(bufp, string_arg, size, pos, regs)
       case stop_nowidth:
 	EXTRACT_NUMBER_AND_INCR(mcnt, p);
 	stackp = stackb + mcnt;
-	d = stackp[-2];
+	d = stackp[-3];
 	POP_FAILURE_POINT();
 	continue;
 
@@ -4015,8 +4015,8 @@ re_match(bufp, string_arg, size, pos, regs)
 	   because didn't fail.  Also remove the register information
 	   put on by the on_failure_jump.  */
       case finalize_jump:
-	if (stackp > stackb && stackp[-2] == d) {
-	  p = stackp[-3];
+	if (stackp > stackb && stackp[-3] == d) {
+	  p = stackp[-4];
 	  POP_FAILURE_POINT();
 	  continue;
 	}
@@ -4032,7 +4032,7 @@ re_match(bufp, string_arg, size, pos, regs)
       case jump:
       nofinalize:
         EXTRACT_NUMBER_AND_INCR(mcnt, p);
-        if (mcnt < 0 && stackp > stackb && stackp[-2] == d) /* avoid infinite loop */
+        if (mcnt < 0 && stackp > stackb && stackp[-3] == d) /* avoid infinite loop */
 	   goto fail;
         p += mcnt;
         continue;
@@ -4123,7 +4123,7 @@ re_match(bufp, string_arg, size, pos, regs)
       case finalize_push:
 	POP_FAILURE_POINT();
 	EXTRACT_NUMBER_AND_INCR(mcnt, p);
-        if (mcnt < 0 && stackp > stackb  && stackp[-2] == d) /* avoid infinite loop */
+        if (mcnt < 0 && stackp > stackb  && stackp[-3] == d) /* avoid infinite loop */
 	   goto fail;
 	PUSH_FAILURE_POINT(p + mcnt, d);
 	stackp[-1] = NON_GREEDY;
@@ -4288,11 +4288,12 @@ re_match(bufp, string_arg, size, pos, regs)
 
       /* If this failure point is from a dummy_failure_point, just
 	 skip it.  */
-      if (stackp[-3] == 0 || (best_regs_set && stackp[-1] == NON_GREEDY)) {
+      if (stackp[-4] == 0 || (best_regs_set && stackp[-1] == NON_GREEDY)) {
 	POP_FAILURE_POINT();
 	goto fail;
       }
-      stackp--;		/* discard flag */
+      stackp--;		/* discard greedy flag */
+      options = (int)*--stackp;
       d = *--stackp;
       p = *--stackp;
       /* Restore register info.  */