1 files changed, 32 insertions, 42 deletions

diff --git a/editors/patch.c b/editors/patch.c
index 4fadbb8fe..1d4a2554e 100644
--- a/editors/patch.c
+++ b/editors/patch.c
@@ -56,75 +56,64 @@
 
 #include "libbb.h"
 
+
+// libbb candidate?
+
 struct double_list {
         struct double_list *next;
         struct double_list *prev;
         char *data;
 };
 
-// Return the first item from the list, advancing the list (which must be called
-// as &list)
-static
-void *TOY_llist_pop(void *list)
-{
-        // I'd use a void ** for the argument, and even accept the typecast in all
-        // callers as documentation you need the &, except the stupid compiler
-        // would then scream about type-punned pointers.  Screw it.
-        void **llist = (void **)list;
-        void **next = (void **)*llist;
-        *llist = *next;
-
-        return (void *)next;
-}
-
 // Free all the elements of a linked list
-// if freeit!=NULL call freeit() on each element before freeing it.
+// Call freeit() on each element before freeing it.
 static
-void TOY_llist_free(void *list, void (*freeit)(void *data))
+void dlist_free(struct double_list *list, void (*freeit)(void *data))
 {
         while (list) {
-                void *pop = TOY_llist_pop(&list);
-                if (freeit) freeit(pop);
-                else free(pop);
-
-                // End doubly linked list too.
-                if (list==pop) break;
+                void *pop = list;
+                list = list->next;
+                freeit(pop);
+                // Bail out also if list is circular.
+                if (list == pop) break;
         }
 }
-//Override bbox's names
-#define llist_pop TOY_llist_pop
-#define llist_free TOY_llist_free
 
-// Add an entry to the end off a doubly linked list
+// Add an entry before "list" element in (circular) doubly linked list
 static
 struct double_list *dlist_add(struct double_list **list, char *data)
 {
-        struct double_list *line = xmalloc(sizeof(struct double_list));
+        struct double_list *llist;
+        struct double_list *line = xmalloc(sizeof(*line));
 
         line->data = data;
-        if (*list) {
-                line->next = *list;
-                line->prev = (*list)->prev;
-                (*list)->prev->next = line;
-                (*list)->prev = line;
-        } else *list = line->next = line->prev = line;
+        llist = *list;
+        if (llist) {
+                struct double_list *p;
+                line->next = llist;
+                p = line->prev = llist->prev;
+                // (list is circular, we assume p is never NULL)
+                p->next = line;
+                llist->prev = line;
+        } else
+                *list = line->next = line->prev = line;
 
         return line;
 }
 
 
-
 struct globals {
         char *infile;
         long prefix;
 
         struct double_list *current_hunk;
+
         long oldline, oldlen, newline, newlen;
         long linenum;
-        int context, state, filein, fileout, hunknum;
+        int context, state, hunknum;
+        int filein, fileout;
         char *tempname;
 
-        // was toys.foo:
         int exitval;
 };
 #define TT (*ptr_to_globals)
@@ -193,7 +182,6 @@ static void finish_oldfile(void)
 static void fail_hunk(void)
 {
         if (!TT.current_hunk) return;
-        TT.current_hunk->prev->next = NULL;
 
         fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline);
         TT.exitval = 1;
@@ -202,7 +190,8 @@ static void fail_hunk(void)
         // this file and advance to next file.
 
         TT.state = 2;
-        llist_free(TT.current_hunk, do_line);
+        TT.current_hunk->prev->next = NULL;
+        dlist_free(TT.current_hunk, do_line);
         TT.current_hunk = NULL;
 
         // Abort the copy and delete the temporary file.
@@ -308,7 +297,8 @@ static int apply_one_hunk(void)
                                         fdprintf(2, "NOT: %s\n", plist->data);
 
                                 TT.state = 3;
-                                check = llist_pop(&buf);
+                                check = buf;
+                                buf = buf->next;
                                 check->prev->next = buf;
                                 buf->prev = check->prev;
                                 do_line(check);
@@ -335,13 +325,13 @@ static int apply_one_hunk(void)
 out:
         // We have a match.  Emit changed data.
         TT.state = "-+"[reverse ^ dummy_revert];
-        llist_free(TT.current_hunk, do_line);
+        dlist_free(TT.current_hunk, do_line);
         TT.current_hunk = NULL;
         TT.state = 1;
 done:
         if (buf) {
                 buf->prev->next = NULL;
-                llist_free(buf, do_line);
+                dlist_free(buf, do_line);
         }
 
         return TT.state;