Fixed crash on deselection of deleted client.

Added current_client pointer to JBWMClient.

JBWMClient.h

@@ -12,6 +12,7 @@
 struct JBWMScreen;
 struct JBWMClient {
     struct JBWMClient ** head; // store to avoid call overhead
+    struct JBWMClient ** current_client;
     struct JBWMClient * next;
     struct JBWMScreen * screen;
     struct JBWMClientTitleBar tb;

button_event.c

@@ -9,8 +9,7 @@
 #include "log.h"
 #include "title_bar.h"
 #include "wm_state.h"
-static void handle_title_bar_button(XButtonEvent * e,
-    struct JBWMClient * c, struct JBWMClient ** current_client)
+static void handle_title_bar_button(XButtonEvent * e, struct JBWMClient * c)
 {
     JBWM_LOG("e->window: %d, c->title_bar: %d, e->subwindow: %d",
         (int)e->window, (int)c->tb.win, (int)e->subwindow);
@@ -24,13 +23,12 @@ static void handle_title_bar_button(XButtonEvent * e,
     else if (e->subwindow == c->tb.shade && !o->no_shade)
         jbwm_toggle_shade(c);
     else if (e->subwindow == c->tb.stick)
-        jbwm_toggle_sticky(c, current_client);
+        jbwm_toggle_sticky(c);
     else
         jbwm_drag(c, false);
 }
 __attribute__((nonnull))
-void jbwm_handle_button_event(XButtonEvent * e,
-    struct JBWMClient * c, struct JBWMClient ** current_client)
+void jbwm_handle_button_event(XButtonEvent * e, struct JBWMClient * c)
 {
     JBWM_LOG("jbwm_handle_button_event");
     const bool fs = c->opt.fullscreen;
@@ -40,7 +38,7 @@ void jbwm_handle_button_event(XButtonEvent * e,
         if (fs)
             XRaiseWindow(d, c->parent);
         else
-            handle_title_bar_button(e, c, current_client);
+            handle_title_bar_button(e, c);
         break;
     case Button2:
         XLowerWindow(d, c->parent);

button_event.h

@@ -6,7 +6,6 @@
 #define JBWM_BUTTON_EVENT_H
 #include <X11/Xlib.h>
 struct JBWMClient;
-void jbwm_handle_button_event(XButtonEvent * e,
-    struct JBWMClient * c, struct JBWMClient ** current_client)
+void jbwm_handle_button_event(XButtonEvent * e, struct JBWMClient * c)
     __attribute__((nonnull));
 #endif /* JBWM_BUTTON_EVENT_H */

client.c

@@ -14,21 +14,17 @@
 #include "wm_state.h"
 #include <X11/Xatom.h>
 #include <X11/Xutil.h>
-/*  Relink client linked list to exclude c */
-void jbwm_relink_client_list(struct JBWMClient * c,
-    struct JBWMClient ** head_client)
+/* Relink c's linked list to exclude c.
+ * Note:  As *c and *i may alias each other, use of 'restrict'
+ * in relink would be invalid. */
+static void relink(const struct JBWMClient * c, struct JBWMClient * i)
 {
-    struct JBWMClient *i, *prev;
-    for (i=*head_client, prev=NULL; i; prev=i, i=i->next) {
-        if (i==c) {
-           if (i==*head_client) { // prev == NULL in this case
-               *head_client=i->next;
-           } else {
-               prev->next=i->next;
-           } 
-           break;
-        }
-    }
+    if (*(c->current_client) == c)
+        *(c->current_client) = NULL; // flag as invalid
+    if (i == c) /* c is head client.  */
+        *(c->head) = c->next; /* removed first client. */
+    if (i && i->next)
+        relink(c, i->next != c ? i->next : (i->next = c->next));
 }
 void jbwm_set_client_vdesk(struct JBWMClient * restrict c, uint8_t desktop)
 {
@@ -55,12 +51,11 @@ struct JBWMClient * jbwm_find_client(
     return head;
 }
 
-void jbwm_toggle_sticky(struct JBWMClient * restrict c,
-    struct JBWMClient ** current_client)
+void jbwm_toggle_sticky(struct JBWMClient * restrict c)
 {
     if(c){
         c->opt.sticky ^= true; /*  toggle */
-        jbwm_select_client(c,current_client);
+        jbwm_select_client(c);
         jbwm_update_title_bar(c);
         {
             Display *d;
@@ -85,7 +80,9 @@ void jbwm_client_free(struct JBWMClient * c, struct JBWMClient ** head_client)
     XRemoveFromSaveSet(d, w);
     if(parent)
         XDestroyWindow(d, parent);
-    jbwm_relink_client_list(c, head_client);
+    relink(c, *head_client);
+    c->screen=NULL;
+    c->head=NULL;
     free(c);
 }
 void jbwm_hide_client(const struct JBWMClient * restrict c)

client.h

@@ -13,13 +13,9 @@ void jbwm_client_free(struct JBWMClient * c,
 /*  Get the client with input focus. */
 //struct JBWMClient * jbwm_get_current_client(void);
 void jbwm_hide_client(const struct JBWMClient * restrict c);
-/*  Relink client linked list to exclude c */
-void jbwm_relink_client_list(struct JBWMClient * c,
-    struct JBWMClient ** head_client);
 /*  Move the client to the specified virtual desktop */
 void jbwm_set_client_vdesk(struct JBWMClient * restrict c, uint8_t desktop);
-void jbwm_toggle_sticky(struct JBWMClient * restrict c,
-    struct JBWMClient ** current_client);
+void jbwm_toggle_sticky(struct JBWMClient * restrict c);
 void jbwm_restore_client(const struct JBWMClient * restrict c);
 __attribute__((pure))
 /* Return the client that has specified window as either window or parent.

events.c

@@ -89,11 +89,10 @@ static void jbwm_handle_ConfigureRequest(XEvent * ev, struct JBWMClient * c)
     if (c)
         jbwm_move_resize(c);
 }
-static void jbwm_handle_EnterNotify(XEvent * ev, struct JBWMClient * c,
-    struct JBWMClient ** current_client)
+static void jbwm_handle_EnterNotify(XEvent * ev, struct JBWMClient * c)
 {
     if (c && ev->xcrossing.window == c->parent)
-        jbwm_select_client(c, current_client);
+        jbwm_select_client(c);
 }
 static void jbwm_handle_Expose(XEvent * ev, struct JBWMClient * c)
 {
@@ -130,10 +129,10 @@ void jbwm_events_loop(struct JBWMScreen * s, struct JBWMClient ** head_client,
             break;
         case ButtonPress:
             if(c)
-                jbwm_handle_button_event(&ev.xbutton, c, current_client);
+                jbwm_handle_button_event(&ev.xbutton, c);
             break;
         case EnterNotify:
-            jbwm_handle_EnterNotify(&ev, c, current_client);
+            jbwm_handle_EnterNotify(&ev, c);
             break;
         case Expose:
             jbwm_handle_Expose(&ev,c);
@@ -156,7 +155,7 @@ void jbwm_events_loop(struct JBWMScreen * s, struct JBWMClient ** head_client,
             jbwm_handle_ColormapNotify(&ev,c);
             break;
         case ClientMessage:
-            jbwm_ewmh_handle_client_message(&ev.xclient, c, current_client);
+            jbwm_ewmh_handle_client_message(&ev.xclient, c);
             break;
 #ifdef DEBUG
         default:

ewmh_client.c

@@ -17,7 +17,7 @@ static void handle_moveresize(XClientMessageEvent * e)
        l[0]: bits 0-7 idicate gravity,
        l[0]: bits 8-11 use x, y, width, height, respectively
        l[0]: bits 12-15 indicate the source,
-     */
+       */
     enum {
         SRC_SHIFT = 12, SRC_MASK = 3, VM_SHIFT = 8, VM_MASK = 0xf,
         USER_ACTION = 2
@@ -36,10 +36,10 @@ static void handle_moveresize(XClientMessageEvent * e)
 }
 // returns true if handled, false if not
 static bool client_specific_message(XClientMessageEvent * e,
-    struct JBWMClient * restrict c, struct JBWMClient ** current_client,
-    const Atom t)
+    struct JBWMClient * restrict c, const Atom t)
 {
-    Display * d = e->display;
+    Display * d;
+    d = e->display;
     jbwm_print_atom(d, t, __FILE__, __LINE__);
     if (t == jbwm_atoms[JBWM_NET_WM_DESKTOP])
         jbwm_set_client_vdesk(c, e->data.l[0]);
@@ -50,7 +50,7 @@ static bool client_specific_message(XClientMessageEvent * e,
     } else if (t == jbwm_atoms[JBWM_NET_WM_STATE])
         jbwm_ewmh_handle_wm_state_changes(e, c);
     else if (t == jbwm_atoms[JBWM_NET_ACTIVE_WINDOW])
-        jbwm_select_client(c, current_client);
+        jbwm_select_client(c);
     else if (t == jbwm_atoms[JBWM_NET_CLOSE_WINDOW])
         jbwm_send_wm_delete(c);
     else
@@ -71,11 +71,11 @@ static void debug_client_message(XClientMessageEvent * e)
 #define debug_client_message(e)
 #endif//JBWM_DEBUG_EWMH_STATE&&DEBUG
 void jbwm_ewmh_handle_client_message(XClientMessageEvent * e,
-    struct JBWMClient * c, struct JBWMClient ** current_client)
+    struct JBWMClient * c)
 {
     const Atom t = e->message_type;
     debug_client_message(e);
-    if(client_specific_message(e, c, current_client, t))
+    if(client_specific_message(e, c, t))
         return;
     if (t == jbwm_atoms[JBWM_NET_CURRENT_DESKTOP]) {
         jbwm_set_vdesk(c->screen, *(c->head), e->data.l[0]);

ewmh_client.h

@@ -4,5 +4,5 @@
 #include <X11/Xlib.h>
 struct JBWMClient;
 void jbwm_ewmh_handle_client_message(XClientMessageEvent * e,
-    struct JBWMClient * c, struct JBWMClient ** current_client);
+    struct JBWMClient * c);
 #endif//!JBWM_EWMH_CLIENT_H

jbwm.c

@@ -61,16 +61,15 @@ static Window * get_windows(Display * dpy, const Window root,
     return w;
 }
 static void setup_clients(Display * d, struct JBWMScreen * s,
-    struct JBWMClient ** head_client,
-    struct JBWMClient ** current_client)
+    struct JBWMClient ** head_client, struct JBWMClient ** current_client)
 {
     uint16_t n;
     Window * w = get_windows(d, RootWindow(d, s->id), &n);
     JBWM_LOG("Started with %d clients", n);
     if (w) { // Avoid segmentation fault on empty list.
         while(n--)
             if(check_redirect(d,w[n]))
-                jbwm_new_client(s,head_client, current_client,w[n]);
+                jbwm_new_client(s, head_client, current_client, w[n]);
         XFree(w);
     }
 }

key_event.c

@@ -152,7 +152,7 @@ static void handle_client_key_event(struct JBWMClient ** current_client,
         (c->opt.max_vert ? jbwm_set_not_vert : jbwm_set_vert)(c);
         break;
     case JBWM_KEY_STICK:
-        jbwm_toggle_sticky(c, current_client);
+        jbwm_toggle_sticky(c);
         break;
     case JBWM_KEY_MOVE:
         jbwm_drag(c, false);
@@ -162,11 +162,10 @@ static void handle_client_key_event(struct JBWMClient ** current_client,
         break;
     }
 }
-static void warp_to(struct JBWMClient * restrict c,
-    struct JBWMClient ** current_client){
+static void warp_to(struct JBWMClient * restrict c) {
     point(c, 0, 0);
     point(c, c->size.width-1, c->size.height-1);
-    jbwm_select_client(c, current_client);
+    jbwm_select_client(c);
 }
 static void next(struct JBWMClient * c,
     struct JBWMClient ** current_client, uint8_t const v){
@@ -178,7 +177,7 @@ static void next(struct JBWMClient * c,
         if(c->vdesk != v)
             next(c, current_client, v);
         else
-            warp_to(c, current_client);
+            warp_to(c);
     }
 }
 static void cond_set_vdesk(struct JBWMClient * c,

new.c

@@ -35,12 +35,12 @@ static uint8_t wm_desktop(Display * d, const Window w, int32_t vdesk)
     JBWM_LOG("wm_desktop(w: %d): vdesk is %d\n", (int) w, vdesk);
     return vdesk;
 }
-static inline uint8_t get_vdesk(struct JBWMClient * restrict c)
+static inline uint8_t get_vdesk(struct JBWMClient *  c)
 {
     return wm_desktop(c->screen->display, c->window, c->screen->vdesk);
 }
 __attribute__((nonnull))
-static Window get_parent(struct JBWMClient * restrict c)
+static Window get_parent(struct JBWMClient *  c)
 {
     enum {
         CFP = CopyFromParent,
@@ -61,7 +61,7 @@ static inline void reparent_window(Display * d, Window parent, Window window)
     XReparentWindow(d, window, parent, 0, 0);
     XMapWindow(d, window);
 }
-static void reparent(struct JBWMClient * restrict c)
+static void reparent(struct JBWMClient *  c)
 {
     JBWM_LOG("reparent()");
     jbwm_new_shaped_client(c);
@@ -73,7 +73,7 @@ static void reparent(struct JBWMClient * restrict c)
 static struct JBWMClient * get_JBWMClient(const Window w,
     struct JBWMScreen * s, struct JBWMClient ** head_client)
 {
-    struct JBWMClient * restrict c = calloc(1, sizeof(struct JBWMClient));
+    struct JBWMClient *  c = calloc(1, sizeof(struct JBWMClient));
     c->screen=s;
     c->window=w;
     c->head=head_client;
@@ -92,12 +92,14 @@ static void do_grabs(Display * d, const Window w)
 }
 void jbwm_new_client(struct JBWMScreen * s,
     struct JBWMClient ** head_client,
-    struct JBWMClient ** current_client, const Window w)
+    struct JBWMClient ** current_client,
+    const Window w)
 {
-    struct JBWMClient * restrict c = get_JBWMClient(w, s, head_client);
+    struct JBWMClient * c = get_JBWMClient(w, s, head_client);
     JBWM_LOG("jbwm_new_client(..., w: %d)", (int)w);
     /* Prepend client.  */
     c->next=*head_client;
+    c->current_client = current_client;
     *head_client=c;
     do_grabs(s->display, w);
     jbwm_set_client_geometry(c);
@@ -106,7 +108,7 @@ void jbwm_new_client(struct JBWMScreen * s,
     c->vdesk = get_vdesk(c);
     jbwm_snap_client(c);
     jbwm_restore_client(c);
-    jbwm_select_client(c, current_client);
+    jbwm_select_client(c);
     if(c->screen->vdesk!=c->vdesk)
         jbwm_hide_client(c);
 }

select.c

@@ -51,16 +51,18 @@ static void set_active_window_property(struct JBWMClient * c)
         jbwm_atoms[JBWM_NET_ACTIVE_WINDOW], XA_WINDOW, 32,
         PropModeReplace, (unsigned char *)&w, 1);
 }
-void jbwm_select_client(struct JBWMClient * c,
-    struct JBWMClient ** current_client)
+void jbwm_select_client(struct JBWMClient * c)
 {
-    if (!c)
-        return;
-    if (*current_client)
-        set_state_not_focused(*current_client);
-    set_border(c);
-    set_focused(c);
-    set_active_window_property(c);
-    *current_client=c;
+    struct JBWMClient ** current, * prev;
+    current = c->current_client;
+    prev = *current;
+        set_border(c);
+        set_focused(c);
+        set_active_window_property(c);
+        *current = c;
+    if (prev != c) {
+        if (prev)
+            set_state_not_focused(prev);
+    }
 }
 

select.h

@@ -6,6 +6,5 @@
 #define JBWM_SELECT_H
 struct JBWMClient;
 // Set client as that receiving focus
-void jbwm_select_client(struct JBWMClient * c,
-    struct JBWMClient **current_client);
+void jbwm_select_client(struct JBWMClient * c);
 #endif//!JBWM_SELECT_H