Re: Minor change for new isearch code

[Wayne Davison <wayne@tenor.clarinet.com>]

Zoltan Hidvegi writes:
> If I go back in the history, modify a line and start an isearch the
> modifications will disappear.

This is actually a more widespread problem in zsh than just the isearch
code.  If I start to edit a history line and go to another history line
via something like Ctrl-P (previous line in emacs mode) my modifications
will also disappear.  I would like to see this fixed for all functions.

How about this.  Unapply your last patch to zle_hist.c and apply this one
instead.  This code creates a function remember_edits() that remembers
the edits to whatever history line we're on and stashes the real history
line in a linked list for later retrieval (I used a linked list just
because it was memory efficient).  When the user presses return a new
function called forget_edits() restores all the edited history lines to
their original values.

I put a call to remember_edits() in quite a few functions in zle_hist.c,
but if you like this code, there are undoubtedly more functions that will
need to call it.  Also, there may be other functions besides the ones
that had "accept" in their name that require the forget_edits() call.

..wayne..
---8<------8<------8<------8<---cut here--->8------>8------>8------>8---
Index: zle_hist.c
@@ -32,6 +32,62 @@
 #define ZLE
 #include "zsh.h"
 
+struct modified {
+    struct modified *next;
+    char *text;
+    int histnum;
+} *hist_mods;
+
+/**/
+void
+remember_edits(void)
+{
+    if (histline == curhist) {
+	zsfree(curhistline);
+	curhistline = metafy(UTOSCP(line), ll, META_DUP);
+    }
+    else {
+	struct modified *node = hist_mods, *prev = NULL;
+	Histent ent = gethistent(histline);
+
+	while (node && node->histnum < histline) {
+	    prev = node;
+	    node = node->next;
+	}
+	if (!node || node->histnum != histline) {
+	    struct modified *newnode = (struct modified *)zalloc(sizeof *node);
+
+	    newnode->next = node;
+	    newnode->histnum = histline;
+	    newnode->text = ent->text;
+	    if (!prev)
+		hist_mods = newnode;
+	    else
+		prev->next = newnode;
+	} else
+	    free(ent->text);
+
+	ent->text = metafy(UTOSCP(line), ll, META_DUP);
+    }
+}
+
+/**/
+void
+forget_edits(void)
+{
+    struct modified *node, *next;
+    Histent ent;
+
+    for (node = hist_mods; node; node = next) {
+	next = node->next;
+	ent = gethistent(node->histnum);
+	free(ent->text);
+	ent->text = node->text;
+	free((char*)node);
+    }
+    hist_mods = NULL;
+}
+
 /**/
 void
 uphistory(void)
@@ -43,10 +99,7 @@
 	downhistory();
 	return;
     }
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     histline -= mult;
     if (!(s = qgetevent(histline))) {
 	if (unset(NOHISTBEEP))
@@ -281,6 +334,7 @@
 {
     char *s;
 
+    forget_edits();
     if (!(s = qgetevent(histline + 1))) {
 	feep();
 	return;
@@ -301,6 +355,7 @@
 	uphistory();
 	return;
     }
+    remember_edits();
     histline += mult;
     if (!(s = qgetevent(histline))) {
 	if (unset(NOHISTBEEP))
@@ -320,10 +375,7 @@
     int t0, ohistline = histline;
     char *s;
 
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     if (lastcmd & ZLE_HISTSEARCH)
 	t0 = histpos;
     else {
@@ -353,10 +405,7 @@
     int t0, ohistline = histline;
     char *s;
 
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     if (lastcmd & ZLE_HISTSEARCH)
 	t0 = histpos;
     else {
@@ -395,10 +444,7 @@
 {
     char *s;
 
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     if (!(s = qgetevent(firsthist()))) {
 	if (unset(NOHISTBEEP))
 	    feep();
@@ -632,12 +678,8 @@
 
     strcpy(ibuf, ISEARCH_PROMPT);
     memcpy(ibuf + NORM_PROMPT_POS, (dir == 1) ? "fwd" : "bck", 3);
-    if (histline == curhist) {
-	zsfree(curhistline);
-	s = curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
-    else
-	s = qgetevent(histline);
+    remember_edits();
+    s = qgetevent(histline);
     bindtab = mainbindtab;
     pos = metalen(s, cs);
     for (;;) {
@@ -834,6 +876,7 @@
     int t0;
     char *s;
 
+    forget_edits();
     done = 1;
     for (t0 = histline - 2;; t0--) {
 	if (!(s = qgetevent(t0)))
@@ -1024,10 +1067,7 @@
 	return;
     }
     t0 = strlen(visrchstr);
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     for (;;) {
 	histline += visrchsense;
 	if (!(s = qgetevent(histline))) {
@@ -1067,10 +1107,7 @@
     int ohistline = histline;
     char *s;
 
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     for (;;) {
 	histline--;
 	if (!(s = qgetevent(histline))) {
@@ -1098,10 +1135,7 @@
     int ohistline = histline;
     char *s;
 
-    if (histline == curhist) {
-	zsfree(curhistline);
-	curhistline = metafy(UTOSCP(line), ll, META_DUP);
-    }
+    remember_edits();
     for (;;) {
 	histline++;
 	if (!(s = qgetevent(histline))) {
Index: zle_misc.c
@@ -256,6 +256,7 @@
 void
 acceptline(void)
 {
+    forget_edits();
     done = 1;
 }
 
@@ -265,6 +266,7 @@
 {
     pushnode(bufstack, ztrdup((char *)line));
     stackcs = cs;
+    forget_edits();
     done = 1;
 }
 
---8<------8<------8<------8<---cut here--->8------>8------>8------>8---