list: LIST_INSERT_BEFORE: update head if necessary (#4261)

[elogind.git] / src / basic / list.h

diff --git a/src/basic/list.h b/src/basic/list.h
index c68185f5878eaad93d4abba7bb9a1a6107d424cd..c3771a177f70e494b94d868a62056bc5d8f6e6be 100644 (file)
--- a/src/basic/list.h
+++ b/src/basic/list.h
@@ -32,7 +32,7 @@
 #define LIST_HEAD_INIT(head)                                            \
         do {                                                            \
                 (head) = NULL; }                                        \
-        while(false)
+        while (false)
 
 /* Initialize a list item */
 #define LIST_INIT(name,item)                                            \
@@ -40,7 +40,7 @@
                 typeof(*(item)) *_item = (item);                        \
                 assert(_item);                                          \
                 _item->name##_prev = _item->name##_next = NULL;         \
-        } while(false)
+        } while (false)
 
 /* Prepend an item to the list */
 #define LIST_PREPEND(name,head,item)                                    \
@@ -51,7 +51,7 @@
                         _item->name##_next->name##_prev = _item;        \
                 _item->name##_prev = NULL;                              \
                 *_head = _item;                                         \
-        } while(false)
+        } while (false)
 
 /* Append an item to the list */
 #define LIST_APPEND(name,head,item)                                     \
@@ -59,7 +59,7 @@
                 typeof(*(head)) *_tail;                                 \
                 LIST_FIND_TAIL(name,head,_tail);                        \
                 LIST_INSERT_AFTER(name,head,_tail,item);                \
-        } while(false)
+        } while (false)
 
 /* Remove an item from the list */
 #define LIST_REMOVE(name,head,item)                                     \
@@ -75,7 +75,7 @@
                         *_head = _item->name##_next;                    \
                 }                                                       \
                 _item->name##_next = _item->name##_prev = NULL;         \
-        } while(false)
+        } while (false)
 
 /* Find the head of the list */
 #define LIST_FIND_HEAD(name,item,head)                                  \
@@ -119,7 +119,7 @@
                         _b->name##_prev = _a;                           \
                         _a->name##_next = _b;                           \
                 }                                                       \
-        } while(false)
+        } while (false)
 
 /* Insert an item before another one (a = where, b = what) */
 #define LIST_INSERT_BEFORE(name,head,a,b)                               \
@@ -142,10 +142,12 @@
                 } else {                                                \
                         if ((_b->name##_prev = _a->name##_prev))        \
                                 _b->name##_prev->name##_next = _b;      \
+                        else                                            \
+                                *_head = _b;                            \
                         _b->name##_next = _a;                           \
                         _a->name##_prev = _b;                           \
                 }                                                       \
-        } while(false)
+        } while (false)
 
 #define LIST_JUST_US(name,item)                                         \
         (!(item)->name##_prev && !(item)->name##_next)                  \