fix some of the things scan-build[1] found (but not some false positives)

10x

From: Elias Pipping <elias@pipping.org>
[1] http://clang.llvm.org/StaticAnalysis.html

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.229 2008/10/10 21:30:41 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.230 2008/10/13 23:06:01 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -7,7 +7,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R35 2008/10/10
+	@(#)MIRBSD KSH R35 2008/10/13
 description:
 	Check version of shell.
 stdin:

edit.c

@@ -5,7 +5,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.137 2008/10/05 16:06:43 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.138 2008/10/13 23:06:02 tg Exp $");
 
 /* tty driver characters we are interested in */
 typedef struct {
@@ -1517,7 +1517,7 @@ x_emacs(char *buf, size_t len)
 		}
 		i = c | (x_curprefix << 8);
 		x_curprefix = 0;
-		switch (i = (*x_ftab[f].xf_func)(i)) {
+		switch ((*x_ftab[f].xf_func)(i)) {
 		case KSTD:
 			if (!(x_ftab[f].xf_flags & XF_PREFIX))
 				x_last_command = f;
@@ -1727,7 +1727,6 @@ x_delete(int nc, int push)
 		x_push(nb);
 
 	xep -= nb;
-	cp = xcp;
 	memmove(xcp, xcp + nb, xep - xcp + 1);	/* Copies the NUL */
 	x_adj_ok = 0;			/* don't redraw */
 	xlp_valid = false;
@@ -2332,7 +2331,7 @@ x_redraw(int limit)
 		x_displen = xx_cols - 2;
 	}
 	xlp_valid = false;
-	cp = x_lastcp();
+	x_lastcp();
 	x_zots(xbp);
 	if (xbp != xbuf || xep > xlp)
 		limit = xx_cols;

histrap.c

@@ -3,7 +3,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.70 2008/09/30 19:36:16 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.71 2008/10/13 23:06:02 tg Exp $");
 
 /*-
  * MirOS: This is the default mapping type, and need not be specified.
@@ -283,7 +283,7 @@ hist_execute(char *cmd)
 		histsave(&hist_source->line, p, true, true);
 
 		shellf("%s\n", p); /* POSIX doesn't say this is done... */
-		if ((p = q)) /* restore \n (trailing \n not restored) */
+		if (q)		/* restore \n (trailing \n not restored) */
 			q[-1] = '\n';
 	}
 

jobs.c

@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/jobs.c,v 1.36 2008/05/17 19:03:25 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/jobs.c,v 1.37 2008/10/13 23:06:03 tg Exp $");
 
 /* Order important! */
 #define PRUNNING	0
@@ -319,7 +319,8 @@ exchild(struct op *t, int flags, /* used if XPCLOSE or XCCLOSE */ int close_fd)
 			    "exchild: XPIPEI and no last_job - pid %d",
 			    (int)procpid);
 		j = last_job;
-		last_proc->next = p;
+		if (last_proc)
+			last_proc->next = p;
 		last_proc = p;
 	} else {
 		j = new_job(); /* fills in j->job */
@@ -402,18 +403,16 @@ exchild(struct op *t, int flags, /* used if XPCLOSE or XCCLOSE */ int close_fd)
 				    SS_RESTORE_DFL|SS_FORCE);
 		}
 		if (Flag(FBGNICE) && (flags & XBGND))
-			i = nice(4);
+			(void)nice(4);
 		if ((flags & XBGND) && !Flag(FMONITOR)) {
 			setsig(&sigtraps[SIGINT], SIG_IGN,
 			    SS_RESTORE_IGN|SS_FORCE);
 			setsig(&sigtraps[SIGQUIT], SIG_IGN,
 			    SS_RESTORE_IGN|SS_FORCE);
-			if (!(flags & (XPIPEI | XCOPROC))) {
-				int fd = open("/dev/null", 0);
-				if (fd != 0) {
-					(void) ksh_dup2(fd, 0, true);
-					close(fd);
-				}
+			if ((!(flags & (XPIPEI | XCOPROC))) &&
+			    ((i = open("/dev/null", 0)) > 0)) {
+				(void)ksh_dup2(i, 0, true);
+				close(i);
 			}
 		}
 		remove_job(j, "child");	/* in case of $(jobs) command */

misc.c

@@ -6,7 +6,7 @@
 #include <grp.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.85 2008/07/18 11:33:12 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.86 2008/10/13 23:06:03 tg Exp $");
 
 #undef USE_CHVT
 #if defined(TIOCSCTTY) && !defined(MKSH_SMALL)
@@ -773,11 +773,11 @@ pat_scan(const unsigned char *p, const unsigned char *pe, int match_sep)
 			continue;
 		if ((*++p == /*(*/ ')' && nest-- == 0) ||
 		    (*p == '|' && match_sep && nest == 0))
-			return ++p;
+			return (p + 1);
 		if ((*p & 0x80) && vstrchr("*+?@! ", *p & 0x7f))
 			nest++;
 	}
-	return NULL;
+	return (NULL);
 }
 
 int
@@ -1137,7 +1137,7 @@ make_path(const char *cwd, const char *file,
 			for (pend = plist; *pend && *pend != ':'; pend++)
 				;
 			plen = pend - plist;
-			*cdpathp = *pend ? ++pend : NULL;
+			*cdpathp = *pend ? pend + 1 : NULL;
 		}
 
 		if ((use_cdpath == 0 || !plen || plist[0] != '/') &&

sh.h

@@ -100,9 +100,9 @@
 #define __SCCSID(x)	__IDSTRING(sccsid,x)
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.239 2008/10/10 21:30:42 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.240 2008/10/13 23:06:03 tg Exp $");
 #endif
-#define MKSH_VERSION "R35 2008/10/10"
+#define MKSH_VERSION "R35 2008/10/13"
 
 #ifndef MKSH_INCLUDES_ONLY
 

tree.c

@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.19 2008/09/14 20:29:13 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.20 2008/10/13 23:06:04 tg Exp $");
 
 #define INDENT	4
 
@@ -262,7 +262,7 @@ tputS(char *wp, struct shf *shf)
 	 *	COMSUB [(`] ...\0	(handle $ ` \ and maybe " in `...` case)
 	 */
 	while (1)
-		switch ((c = *wp++)) {
+		switch (*wp++) {
 		case EOS:
 			return;
 		case ADELIM:
@@ -541,7 +541,7 @@ wdstrip(const char *wp, bool keepq, bool make_magic)
 	 *	x${foo:-'hi'} -> x${foo:-hi} unless keepq
 	 */
 	while (1)
-		switch ((c = *wp++)) {
+		switch (*wp++) {
 		case EOS:
 			return shf_sclose(&shf); /* null terminates */
 		case ADELIM: