fixed segfault with incomplete WM_CLASS

src/funcs.h

@@ -93,12 +93,15 @@ void StartWindozeCycle(WWindow *wwin, XEvent *event, Bool next);
 char *MakeCPPArgs(char *path);
 #endif
 
+char *StrConcatDot(char *a, char *b);
+
 char *ExpandOptions(WScreen *scr, char *cmdline);
 
 void ExecuteShellCommand(WScreen *scr, char *command);
 
 void StartLogShell(WScreen *scr);
 
+
 Bool IsDoubleClick(WScreen *scr, XEvent *event);
 
 WWindow *NextToFocusAfter(WWindow *wwin);

src/misc.c

@@ -1271,3 +1271,22 @@ UpdateDomainFile(WDDomain *domain)
 }
 
 
+
+char*
+StrConcatDot(char *a, char *b)
+{
+    int len;
+    char *str;
+    
+    if (!a)
+	a = "";
+    if (!b)
+	b = "";
+    
+    len = strlen(a)+strlen(b)+4;
+    str = wmalloc(len);
+    
+    snprintf(str, len, "%s.%s", a, b);
+    
+    return str;
+}

src/window.c

@@ -830,9 +830,9 @@ wManageWindow(WScreen *scr, Window window)
 
 #define ADEQUATE(x) ((x)!=None && (x)!=wwin->client_win && (x)!=fPtr->leader)
 
+	
         PropGetWMClass(wwin->main_window, &class, &instance);
-        buffer = wmalloc(strlen(instance)+strlen(class)+2);
-        sprintf(buffer, "%s.%s", instance, class);
+	buffer = StrConcatDot(instance, class);
 
         index = WMFindInArray(scr->fakeGroupLeaders, matchIdentifier, (void*)buffer);
         if (index != WANotFound) {

src/winspector.c

@@ -527,8 +527,7 @@ saveSettings(WMButton *button, InspectorPanel *panel)
     else if (WMGetButtonSelected(panel->bothRb) != 0) {
         char *buffer;
 
-        buffer = wmalloc(strlen(wwin->wm_instance)+strlen(wwin->wm_class)+2);
-        sprintf(buffer, "%s.%s", wwin->wm_instance, wwin->wm_class);
+	buffer = StrConcatDot(wwin->wm_instance, wwin->wm_class);
         key = WMCreatePLString(buffer);
         wfree(buffer);
     } else if (WMGetButtonSelected(panel->defaultRb) != 0) {
@@ -684,8 +683,7 @@ saveSettings(WMButton *button, InspectorPanel *panel)
             char *class = wapp->main_window_desc->wm_class;
             char *buffer;
 
-            buffer = wmalloc(strlen(instance)+strlen(class)+2);
-            sprintf(buffer, "%s.%s", instance, class);
+	    buffer = StrConcatDot(instance, class);
 	    key2 = WMCreatePLString(buffer);
             wfree(buffer);