PATCH: history delayed drop

[Wayne Davison <wayned@xxxxxxxxxxxxxxxxxxxxx>]

OK, the general consensus I got was that everyone could either live
with or endorse the delayed-drop history change without an extra
option, so I've left it off (we can always add it later, if needed).

Since we still seem to be tweaking several things in zsh prior to
release, I have done some release testing of my patch, uncovered
one more bug, tested it some more, and then checked it into CVS.
Appended is the diff of what I did.

..wayne..

Index: Doc/Zsh/options.yo
@@ -544,18 +544,28 @@
 pindex(HIST_IGNORE_SPACE)
 cindex(history, ignoring spaces)
 item(tt(HIST_IGNORE_SPACE) (tt(-g)))(
-Do not enter command lines into the history list
-if the first character on the line is a space, or if one of
-the expanded aliases contained a leading space.
+Remove command lines from the history list when the first character on
+the line is a space, or when one of the expanded aliases contains a
+leading space.
+Note that the command lingers in the internal history until the next
+command is entered before it vanishes, allowing you to briefly reuse
+or edit the line.  If you want to make it vanish right away without
+entering another command, type a space and press return.
 )
 pindex(HIST_NO_FUNCTIONS)
 item(tt(HIST_NO_FUNCTIONS))(
-Do not store function definitions in the history list.
+Remove function definitions from the history list.
+Note that the function lingers in the internal history until the next
+command is entered before it vanishes, allowing you to briefly reuse
+or edit the definition.
 )
 pindex(HIST_NO_STORE)
 item(tt(HIST_NO_STORE))(
-Remove the tt(history) (tt(fc -l)) command from
-the history when invoked.
+Remove the tt(history) (tt(fc -l)) command from the history list
+when invoked.
+Note that the command lingers in the internal history until the next
+command is entered before it vanishes, allowing you to briefly reuse
+or edit the line.
 )
 pindex(HIST_REDUCE_BLANKS)
 item(tt(HIST_REDUCE_BLANKS))(
Index: Src/hashtable.c
@@ -1480,10 +1480,11 @@
     HashNode oldnode = addhashnode2(ht, nam, nodeptr);
     Histent he = (Histent)nodeptr;
     if (oldnode && oldnode != (HashNode)nodeptr) {
-	if (he->flags & HIST_MAKEUNIQUE
+	if (he->flags & (HIST_MAKEUNIQUE | HIST_TMPSTORE)
 	 || (he->flags & HIST_FOREIGN && (Histent)oldnode == he->up)) {
+	    (void) addhashnode2(ht, oldnode->nam, oldnode); /* restore hash */
 	    he->flags |= HIST_DUP;
-	    addhashnode(ht, oldnode->nam, oldnode); /* Remove the new dup */
+	    he->flags &= ~HIST_MAKEUNIQUE;
 	}
 	else {
 	    oldnode->flags |= HIST_DUP;
Index: Src/hist.c
@@ -794,16 +794,19 @@
 void
 histreduceblanks(void)
 {
-    int i, len, pos, needblank;
+    int i, len, pos, needblank, spacecount = 0;
 
-    for (i = 0, len = 0; i < chwordpos; i += 2) {
+    if (isset(HISTIGNORESPACE))
+	while (chline[spacecount] == ' ') spacecount++;
+
+    for (i = 0, len = spacecount; i < chwordpos; i += 2) {
 	len += chwords[i+1] - chwords[i]
 	     + (i > 0 && chwords[i] > chwords[i-1]);
     }
     if (chline[len] == '\0')
 	return;
 
-    for (i = 0, pos = 0; i < chwordpos; i += 2) {
+    for (i = 0, pos = spacecount; i < chwordpos; i += 2) {
 	len = chwords[i+1] - chwords[i];
 	needblank = (i < chwordpos-2 && chwords[i+2] > chwords[i+1]);
 	if (pos != chwords[i]) {
@@ -1044,8 +1047,10 @@
 	    } else
 		save = 0;
 	}
-	if (chwordpos <= 2 || should_ignore_line(prog))
+	if (chwordpos <= 2)
 	    save = 0;
+	else if (should_ignore_line(prog))
+	    save = -1;
     }
     if (flag & (HISTFLAG_DONE | HISTFLAG_RECALL)) {
 	char *ptr;
@@ -1058,14 +1063,23 @@
 	}
 	if (flag & HISTFLAG_RECALL) {
 	    zpushnode(bufstack, ptr);
-
 	    save = 0;
 	} else
 	    zsfree(ptr);
     }
+    if (save || *chline == ' ') {
+	Histent he;
+	for (he = hist_ring; he && he->flags & HIST_FOREIGN;
+	     he = up_histent(he)) ;
+	if (he && he->flags & HIST_TMPSTORE) {
+	    if (he == hist_ring)
+		curline.histnum = curhist--;
+	    freehistnode((HashNode)he);
+	}
+    }
     if (save) {
 	Histent he;
-	int keepflags;
+	int newflags;
 
 #ifdef DEBUG
 	/* debugging only */
@@ -1081,6 +1095,7 @@
 	    if (isset(HISTREDUCEBLANKS))
 		histreduceblanks();
 	}
+	newflags = save > 0? 0 : HIST_OLD | HIST_TMPSTORE;
 	if ((isset(HISTIGNOREDUPS) || isset(HISTIGNOREALLDUPS)) && hist_ring
 	 && histstrcmp(chline, hist_ring->text) == 0) {
 	    /* This history entry compares the same as the previous.
@@ -1089,18 +1104,16 @@
 	     * timestamp right.  Perhaps, preserve the HIST_OLD flag.
 	     */
 	    he = hist_ring;
-	    keepflags = he->flags & HIST_OLD; /* Avoid re-saving */
+	    newflags |= he->flags & HIST_OLD; /* Avoid re-saving */
 	    freehistdata(he, 0);
 	    curline.histnum = curhist;
-	} else {
-	    keepflags = 0;
+	} else
 	    he = prepnexthistent();
-	}
 
 	he->text = ztrdup(chline);
 	he->stim = time(NULL);
 	he->ftim = 0L;
-	he->flags = keepflags;
+	he->flags = newflags;
 
 	if ((he->nwords = chwordpos/2)) {
 	    he->words = (short *)zalloc(chwordpos * sizeof(short));
@@ -1893,8 +1906,10 @@
 	    } else
 		he->words = (short *)NULL;
 	    addhistnode(histtab, he->text, he);
-	    if (hist_ring != he)
-		curhist--; /* We discarded a foreign duplicate */
+	    if (he->flags & HIST_DUP) {
+		freehistnode((HashNode)he);
+		curhist--;
+	    }
 	}
 	if (start && readflags & HFILE_USE_OPTIONS) {
 	    zsfree(lasthist.text);
@@ -1962,7 +1977,8 @@
     if (out) {
 	for (; he && he->histnum <= xcurhist; he = down_histent(he)) {
 	    if ((writeflags & HFILE_SKIPDUPS && he->flags & HIST_DUP)
-	     || (writeflags & HFILE_SKIPFOREIGN && he->flags & HIST_FOREIGN))
+	     || (writeflags & HFILE_SKIPFOREIGN && he->flags & HIST_FOREIGN)
+	     || he->flags & HIST_TMPSTORE)
 		continue;
 	    if (writeflags & HFILE_SKIPOLD) {
 		if (he->flags & HIST_OLD)
Index: Src/zsh.h
@@ -1252,6 +1252,7 @@
 #define HIST_READ	0x00000004	/* Command was read back from disk*/
 #define HIST_DUP	0x00000008	/* Command duplicates a later line */
 #define HIST_FOREIGN	0x00000010	/* Command came from another shell */
+#define HIST_TMPSTORE	0x00000020	/* Kill when user enters another cmd */
 
 #define GETHIST_UPWARD  (-1)
 #define GETHIST_DOWNWARD  1