41747: Don't create hash entry if just checking existence.

Pass a flag in indicating this case.

5 files changed, 23 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index 049640139..4ed4acefe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-09-25  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 41747: Sr/hist.c, Src/params.c, Src/subst.c. Src/zsh.h: add
+	flag so as not to create hash table when checking existence.
+
 2017-09-24  Daniel Shahaf  <d.s@daniel.shahaf.name>
 
 	* 41755: Doc/Zsh/params.yo: Followup to last: minor clarification
diff --git a/Src/hist.c b/Src/hist.c
index da5a8b29f..177250f31 100644
--- a/Src/hist.c
+++ b/Src/hist.c
@@ -1083,7 +1083,6 @@ hbegin(int dohist)
     } else
 	histactive = HA_ACTIVE | HA_NOINC;
 
-    hf = getsparam("HISTFILE");
     /*
      * For INCAPPENDHISTORYTIME, when interactive, save the history here
      * as it gives a better estimate of the times of commands.
@@ -1104,8 +1103,10 @@ hbegin(int dohist)
      */
     if (isset(INCAPPENDHISTORYTIME) && !isset(SHAREHISTORY) &&
 	!isset(INCAPPENDHISTORY) &&
-	!(histactive & HA_NOINC) && !strin && histsave_stack_pos == 0)
+	!(histactive & HA_NOINC) && !strin && histsave_stack_pos == 0) {
+	hf = getsparam("HISTFILE");
 	savehistfile(hf, 0, HFILE_USE_OPTIONS | HFILE_FAST);
+    }
 }
 
 /**/
diff --git a/Src/params.c b/Src/params.c
index c7514de8a..4d4d08085 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -1204,7 +1204,7 @@ isident(char *s)
 /**/
 static zlong
 getarg(char **str, int *inv, Value v, int a2, zlong *w,
-       int *prevcharlen, int *nextcharlen)
+       int *prevcharlen, int *nextcharlen, int flags)
 {
     int hasbeg = 0, word = 0, rev = 0, ind = 0, down = 0, l, i, ishash;
     int keymatch = 0, needtok = 0, arglen, len, inpar = 0;
@@ -1407,6 +1407,8 @@ getarg(char **str, int *inv, Value v, int a2, zlong *w,
 	if (ishash) {
 	    HashTable ht = v->pm->gsu.h->getfn(v->pm);
 	    if (!ht) {
+		if (flags & SCANPM_CHECKING)
+		    return isset(KSHARRAYS) ? 1 : 0;
 		ht = newparamtable(17, v->pm->node.nam);
 		v->pm->gsu.h->setfn(v->pm, ht);
 	    }
@@ -1848,7 +1850,8 @@ getindex(char **pptr, Value v, int flags)
 	zlong we = 0, dummy;
 	int startprevlen, startnextlen;
 
-	start = getarg(&s, &inv, v, 0, &we, &startprevlen, &startnextlen);
+	start = getarg(&s, &inv, v, 0, &we, &startprevlen, &startnextlen,
+		       flags);
 
 	if (inv) {
 	    if (!v->isarr && start != 0) {
@@ -1922,7 +1925,7 @@ getindex(char **pptr, Value v, int flags)
 
 	    if ((com = (*s == ','))) {
 		s++;
-		end = getarg(&s, &inv, v, 1, &dummy, NULL, NULL);
+		end = getarg(&s, &inv, v, 1, &dummy, NULL, NULL, flags);
 	    } else {
 		end = we ? we : start;
 	    }
diff --git a/Src/subst.c b/Src/subst.c
index 357dc9168..55b5444c6 100644
--- a/Src/subst.c
+++ b/Src/subst.c
@@ -2446,7 +2446,13 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
      */
     if (!subexp || aspar) {
 	char *ov = val;
-
+	int scanflags = hkeys | hvals;
+	if (arrasg)
+	    scanflags |= SCANPM_ASSIGNING;
+	if (qt)
+	    scanflags |= SCANPM_DQUOTED;
+	if (chkset)
+	    scanflags |= SCANPM_CHECKING;
 	/*
 	 * Second argument: decide whether to use the subexpression or
 	 *   the string next on the line as the parameter name.
@@ -2475,9 +2481,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	if (!(v = fetchvalue(&vbuf, (subexp ? &ov : &s),
 			     (wantt ? -1 :
 			      ((unset(KSHARRAYS) || inbrace) ? 1 : -1)),
-			     hkeys|hvals|
-			     (arrasg ? SCANPM_ASSIGNING : 0)|
-			     (qt ? SCANPM_DQUOTED : 0))) ||
+			     scanflags)) ||
 	    (v->pm && (v->pm->node.flags & PM_UNSET)) ||
 	    (v->flags & VALFLAG_EMPTY))
 	    vunset = 1;
diff --git a/Src/zsh.h b/Src/zsh.h
index f7242dd34..b6e2001fb 100644
--- a/Src/zsh.h
+++ b/Src/zsh.h
@@ -1911,6 +1911,7 @@ struct tieddata {
 				  * necessarily want to match multiple
 				  * elements
 				  */
+#define SCANPM_CHECKING   (1<<10) /* Check if set, no need to create */
 /* "$foo[@]"-style substitution
  * Only sign bit is significant
  */