implement completely new multiline code by delaying history store

this commit is valgrind-tested

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.697 2015/07/05 17:04:24 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.698 2015/07/05 19:37:11 tg Exp $
 # -*- mode: sh -*-
 #-
 # Copyright © 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
@@ -30,7 +30,7 @@
 # (2013/12/02 20:39:44) http://openbsd.cs.toronto.edu/cgi-bin/cvsweb/src/regress/bin/ksh/?sortby=date
 
 expected-stdout:
-	@(#)MIRBSD KSH R51 2015/06/28
+	@(#)MIRBSD KSH R51 2015/07/05
 description:
 	Check version of shell.
 stdin:
@@ -39,7 +39,7 @@ name: KSH_VERSION
 category: shell:legacy-no
 ---
 expected-stdout:
-	@(#)LEGACY KSH R51 2015/06/28
+	@(#)LEGACY KSH R51 2015/07/05
 description:
 	Check version of legacy shell.
 stdin:

edit.c

@@ -28,7 +28,7 @@
 
 #ifndef MKSH_NO_CMDLINE_EDITING
 
-__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.286 2015/05/03 11:28:53 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.287 2015/07/05 19:37:13 tg Exp $");
 
 /*
  * in later versions we might use libtermcap for this, but since external
@@ -3054,7 +3054,7 @@ x_edit_line(int c MKSH_A_UNUSED)
 		}
 		if (modified) {
 			*xep = '\0';
-			histsave(&source->line, xbuf, true, true);
+			histsave(&source->line, xbuf, HIST_STORE, true);
 			x_arg = 0;
 		} else
 			x_arg = source->line - (histptr - x_histp);
@@ -4311,8 +4311,8 @@ vi_cmd(int argcnt, const char *cmd)
 					return (-1);
 				if (modified) {
 					es->cbuf[es->linelen] = '\0';
-					histsave(&source->line, es->cbuf, true,
+					histsave(&source->line, es->cbuf,
-					    true);
+					    HIST_STORE, true);
 				} else
 					argcnt = source->line + 1 -
 					    (hlast - hnum);

funcs.c

@@ -38,7 +38,7 @@
 #endif
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.275 2015/07/05 17:50:39 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.276 2015/07/05 19:37:14 tg Exp $");
 
 #if HAVE_KILLPG
 /*
@@ -442,7 +442,7 @@ c_print(const char **wp)
 
 	if (flags & PO_HIST) {
 		Xput(xs, xp, '\0');
-		histsave(&source->line, Xstring(xs, xp), true, false);
+		histsave(&source->line, Xstring(xs, xp), HIST_STORE, false);
 		Xfree(xs, xp);
 	} else {
 		int len = Xlength(xs, xp);
@@ -2076,7 +2076,7 @@ c_read(const char **wp)
 	}
 
 	if (savehist)
-		histsave(&source->line, Xstring(xs, xp), true, false);
+		histsave(&source->line, Xstring(xs, xp), HIST_STORE, false);
 
 	ccp = cp = Xclose(xs, xp);
 	expanding = false;

histrap.c

@@ -27,7 +27,7 @@
 #include <sys/file.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.146 2015/07/05 17:04:26 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.147 2015/07/05 19:37:15 tg Exp $");
 
 Trap sigtraps[ksh_NSIG + 1];
 static struct sigaction Sigact_ign;
@@ -380,7 +380,7 @@ hist_execute(char *cmd, Area *areap)
 		last_line = hist_source->line;
 	}
 
-	histsave(&hist_source->line, cmd, true, true);
+	histsave(&hist_source->line, cmd, HIST_STORE, true);
 	/* now *histptr == cmd without all trailing newlines */
 	afree(cmd, areap);
 	cmd = *histptr;
@@ -620,31 +620,67 @@ histsync(void)
  * save command in history
  */
 void
-histsave(int *lnp, const char *cmd, bool dowrite MKSH_A_UNUSED, bool ignoredups)
+histsave(int *lnp, const char *cmd, int svmode, bool ignoredups)
 {
-	char **hp;
+	static char *enqueued = NULL;
-	char *c;
+	char **hp, *c;
 	const char *ccp;
 
+	if (svmode == HIST_APPEND) {
+		if (!enqueued)
+			svmode = HIST_STORE;
+	} else if (enqueued) {
+		c = enqueued;
+		enqueued = NULL;
+		--*lnp;
+		histsave(lnp, c, HIST_STORE, true);
+		afree(c, APERM);
+	}
+
+	if (svmode == HIST_FLUSH)
+		return;
+
 	ccp = cmd + strlen(cmd);
 	while (ccp > cmd && ccp[-1] == '\n')
 		--ccp;
 	strndupx(c, cmd, ccp - cmd, APERM);
 
-	if (ignoredups && !strcmp(c, *histptr)
+	if (svmode != HIST_APPEND) {
+		if (ignoredups && !strcmp(c, *histptr)
 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
-	    && !histsync()
+		    && !histsync()
 #endif
-	    ) {
+		    ) {
+			afree(c, APERM);
+			return;
+		}
+		++*lnp;
+	}
+
+#if HAVE_PERSISTENT_HISTORY
+	if (svmode == HIST_STORE && histfd != -1)
+		writehistfile(*lnp, c);
+#endif
+
+	if (svmode == HIST_QUEUE || svmode == HIST_APPEND) {
+		size_t nenq, ncmd;
+
+		if (!enqueued) {
+			if (*c)
+				enqueued = c;
+			else
+				afree(c, APERM);
+			return;
+		}
+
+		nenq = strlen(enqueued);
+		ncmd = strlen(c);
+		enqueued = aresize(enqueued, nenq + 1 + ncmd + 1, APERM);
+		enqueued[nenq] = '\n';
+		memcpy(enqueued + nenq + 1, c, ncmd + 1);
 		afree(c, APERM);
 		return;
 	}
-	++*lnp;
-
-#if HAVE_PERSISTENT_HISTORY
-	if (dowrite && histfd != -1)
-		writehistfile(*lnp, c);
-#endif
 
 	hp = histptr;
 
@@ -855,7 +891,7 @@ histload(Source *s, unsigned char *base, size_t bytes)
 		}
 	} else {
 		s->line = lno--;
-		histsave(&lno, (char *)(base + 4), false, false);
+		histsave(&lno, (char *)(base + 4), HIST_NOTE, false);
 	}
 	/* advance base pointer past NUL */
 	bytes -= ++cp - base;

lex.c

@@ -23,7 +23,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.202 2015/07/05 13:49:42 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.203 2015/07/05 19:37:16 tg Exp $");
 
 /*
  * states while lexing word
@@ -1461,11 +1461,16 @@ getsc_line(Source *s)
 		if (s->type == SFILE)
 			shf_fdclose(s->u.shf);
 		s->str = NULL;
-	} else if (interactive && *s->str &&
+	} else if (interactive && *s->str) {
-	    (cur_prompt != PS1 || !ctype(*s->str, C_IFS | C_IFSWS))) {
+		if (cur_prompt != PS1)
-		histsave(&s->line, s->str, true, true);
+			histsave(&s->line, s->str, HIST_APPEND, true);
+		else if (!ctype(*s->str, C_IFS | C_IFSWS))
+			histsave(&s->line, s->str, HIST_QUEUE, true);
 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
+		else
+			goto check_for_sole_return;
 	} else if (interactive && cur_prompt == PS1) {
+ check_for_sole_return:
 		cp = Xstring(s->xs, xp);
 		while (*cp && ctype(*cp, C_IFSWS))
 			++cp;

main.c

@@ -34,7 +34,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.293 2015/04/29 20:07:33 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.294 2015/07/05 19:37:16 tg Exp $");
 
 extern char **environ;
 
@@ -803,6 +803,8 @@ shell(Source * volatile s, volatile bool toplevel)
 			set_prompt(PS1, s);
 		}
 		t = compile(s, sfirst);
+		if (interactive)
+			histsave(&s->line, NULL, HIST_FLUSH, true);
 		sfirst = false;
 		if (!t)
 			goto source_no_tree;

mksh.1

@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.371 2015/07/05 17:50:40 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.372 2015/07/05 19:37:17 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.160 2015/07/04 13:27:04 feinerer Exp $
 .\"-
 .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
@@ -1859,7 +1859,8 @@ below for more information.
 .It Ev HISTFILE
 The name of the file used to store command history.
 When assigned to or unset, the file is opened, history is truncated
-then loaded from the file; subsequent new lines are appended.
+then loaded from the file; subsequent new commands (possibly consisting
+of several lines) are appended once they successfully compiled.
 Also, several invocations of the shell will share history if their
 .Ev HISTFILE
 parameters all point to the same file.

sh.h

@@ -169,9 +169,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.732 2015/07/05 14:43:08 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.733 2015/07/05 19:37:18 tg Exp $");
 #endif
-#define MKSH_VERSION "R51 2015/06/28"
+#define MKSH_VERSION "R51 2015/07/05"
 
 /* arithmetic types: C implementation */
 #if !HAVE_CAN_INTTYPES
@@ -1625,6 +1625,13 @@ EXTERN char **history;		/* saved commands */
 EXTERN char **histptr;		/* last history item */
 EXTERN mksh_ari_t histsize;	/* history size */
 
+/* flags to histsave */
+#define HIST_FLUSH	0
+#define HIST_QUEUE	1
+#define HIST_APPEND	2
+#define HIST_STORE	3
+#define HIST_NOTE	4
+
 /* user and system time of last j_waitjed job */
 EXTERN struct timeval j_usrtime, j_systime;
 
@@ -1751,7 +1758,7 @@ void hist_init(Source *);
 #if HAVE_PERSISTENT_HISTORY
 void hist_finish(void);
 #endif
-void histsave(int *, const char *, bool, bool);
+void histsave(int *, const char *, int, bool);
 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
 bool histsync(void);
 #endif