From ecc85832f8b4d8278b0a17aa62b0c8a9f81461e4 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Thu, 20 Feb 2020 10:06:20 +0100
Subject: [PATCH] ash: expand: Merge syntax/quotes in memtodest with flags

Upstream commit:

    Date: Mon, 28 May 2018 00:17:39 +0800
    expand: Merge syntax/quotes in memtodest with flags

    The function arguments syntax and quotes are both derived from
    the expansion flags.  As syntax is only used by memtodest we do
    not need to maintain it outside of the function at all.

    The only place that uses something other than BASESYNTAX or DQSYNTAX
    is exptilde.  However in that case DQSYNTAX has exactly the same
    effect as SQSYNTAX.

    This patch merges these two arguments into a single flags.  The
    macro QUOTES_KEEPNUL has been renamed to EXP_KEEPNUL in order
    to keep the namespace separate.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 shell/ash.c | 40 +++++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/shell/ash.c b/shell/ash.c
index 81d2422d6..6087416ab 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6030,6 +6030,8 @@ static int substr_atoi(const char *s)
 #define EXP_VARTILDE2   0x20    /* expand tildes after colons only */
 #define EXP_WORD        0x40    /* expand word in parameter expansion */
 #define EXP_QUOTED      0x100   /* expand word in double quotes */
+#define EXP_KEEPNUL     0x200   /* do not skip NUL characters */
+
 /*
  * rmescape() flags
  */
@@ -6040,8 +6042,6 @@ static int substr_atoi(const char *s)
 
 /* Add CTLESC when necessary. */
 #define QUOTES_ESC     (EXP_FULL | EXP_CASE)
-/* Do not skip NUL characters. */
-#define QUOTES_KEEPNUL EXP_TILDE
 
 /*
  * Structure specifying which parts of the string should be searched
@@ -6348,27 +6348,28 @@ preglob(const char *pattern, int flag)
  * Put a string on the stack.
  */
 static void
-memtodest(const char *p, size_t len, int syntax, int quotes)
+memtodest(const char *p, size_t len, int flags)
 {
+	int syntax = flags & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
 	char *q;
 
 	if (!len)
 		return;
 
-	q = makestrspace((quotes & QUOTES_ESC) ? len * 2 : len, expdest);
+	q = makestrspace(len * 2, expdest);
 
 	do {
 		unsigned char c = *p++;
 		if (c) {
-			if (quotes & QUOTES_ESC) {
+			if (flags & QUOTES_ESC) {
 				int n = SIT(c, syntax);
 				if (n == CCTL
-				 || (syntax != BASESYNTAX && n == CBACK)
+				 || ((flags & EXP_QUOTED) && n == CBACK)
 				) {
 					USTPUTC(CTLESC, q);
 				}
 			}
-		} else if (!(quotes & QUOTES_KEEPNUL))
+		} else if (!(flags & EXP_KEEPNUL))
 			continue;
 		USTPUTC(c, q);
 	} while (--len);
@@ -6377,10 +6378,10 @@ memtodest(const char *p, size_t len, int syntax, int quotes)
 }
 
 static size_t
-strtodest(const char *p, int syntax, int quotes)
+strtodest(const char *p, int flags)
 {
 	size_t len = strlen(p);
-	memtodest(p, len, syntax, quotes);
+	memtodest(p, len, flags);
 	return len;
 }
 
@@ -6448,13 +6449,12 @@ removerecordregions(int endoff)
 }
 
 static char *
-exptilde(char *startp, char *p, int flags)
+exptilde(char *startp, char *p, int flag)
 {
 	unsigned char c;
 	char *name;
 	struct passwd *pw;
 	const char *home;
-	int quotes = flags & QUOTES_ESC;
 
 	name = p + 1;
 
@@ -6465,7 +6465,7 @@ exptilde(char *startp, char *p, int flags)
 		case CTLQUOTEMARK:
 			return startp;
 		case ':':
-			if (flags & EXP_VARTILDE)
+			if (flag & EXP_VARTILDE)
 				goto done;
 			break;
 		case '/':
@@ -6486,7 +6486,7 @@ exptilde(char *startp, char *p, int flags)
 	if (!home)
 		goto lose;
 	*p = c;
-	strtodest(home, SQSYNTAX, quotes);
+	strtodest(home, flag | EXP_QUOTED);
 	return p;
  lose:
 	*p = c;
@@ -6586,7 +6586,6 @@ expbackq(union node *cmd, int flag)
 	char *p;
 	char *dest;
 	int startloc;
-	int syntax = flag & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
 	struct stackmark smark;
 
 	INT_OFF;
@@ -6600,7 +6599,7 @@ expbackq(union node *cmd, int flag)
 	if (i == 0)
 		goto read;
 	for (;;) {
-		memtodest(p, i, syntax, flag & QUOTES_ESC);
+		memtodest(p, i, flag);
  read:
 		if (in.fd < 0)
 			break;
@@ -7309,11 +7308,10 @@ varvalue(char *name, int varflags, int flags, int quoted)
 	int sep;
 	int subtype = varflags & VSTYPE;
 	int discard = subtype == VSPLUS || subtype == VSLENGTH;
-	int quotes = (discard ? 0 : (flags & QUOTES_ESC)) | QUOTES_KEEPNUL;
-	int syntax;
 
+	flags |= EXP_KEEPNUL;
+	flags &= discard ? ~QUOTES_ESC : ~0;
 	sep = (flags & EXP_FULL) << CHAR_BIT;
-	syntax = quoted ? DQSYNTAX : BASESYNTAX;
 
 	switch (*name) {
 	case '$':
@@ -7379,11 +7377,11 @@ varvalue(char *name, int varflags, int flags, int quoted)
 		if (!ap)
 			return -1;
 		while ((p = *ap++) != NULL) {
-			len += strtodest(p, syntax, quotes);
+			len += strtodest(p, flags);
 
 			if (*ap && sep) {
 				len++;
-				memtodest(&sepc, 1, syntax, quotes);
+				memtodest(&sepc, 1, flags);
 			}
 		}
 		break;
@@ -7410,7 +7408,7 @@ varvalue(char *name, int varflags, int flags, int quoted)
 		if (!p)
 			return -1;
 
-		len = strtodest(p, syntax, quotes);
+		len = strtodest(p, flags);
 #if ENABLE_UNICODE_SUPPORT
 		if (subtype == VSLENGTH && len > 0) {
 			reinit_unicode_for_ash();