basic/strv: use SWAP_TWO() macro (#3602)

[elogind.git] / src / basic / strv.c

diff --git a/src/basic/strv.c b/src/basic/strv.c
index 5c8261d9210d240e767c9c0af831c1dec106a2d9..ba4d697b106959cc6054992ad11c7f374bb564a5 100644 (file)
--- a/src/basic/strv.c
+++ b/src/basic/strv.c
@@ -319,7 +319,7 @@ char **strv_split_newlines(const char *s) {
                 return l;
 
         if (isempty(l[n - 1]))
-                l[n-1] = mfree(l[n-1]);
+                l[n - 1] = mfree(l[n - 1]);
 
         return l;
 }
@@ -375,7 +375,7 @@ char *strv_join(char **l, const char *separator) {
 
         n = 0;
         STRV_FOREACH(s, l) {
-                if (n != 0)
+                if (s != l)
                         n += k;
                 n += strlen(*s);
         }
@@ -386,7 +386,7 @@ char *strv_join(char **l, const char *separator) {
 
         e = r;
         STRV_FOREACH(s, l) {
-                if (e != r)
+                if (s != l)
                         e = stpcpy(e, separator);
 
                 e = stpcpy(e, *s);
@@ -566,6 +566,42 @@ int strv_extend(char ***l, const char *value) {
         return strv_consume(l, v);
 }
 
+int strv_extend_front(char ***l, const char *value) {
+        size_t n, m;
+        char *v, **c;
+
+        assert(l);
+
+        /* Like strv_extend(), but prepends rather than appends the new entry */
+
+        if (!value)
+                return 0;
+
+        n = strv_length(*l);
+
+        /* Increase and overflow check. */
+        m = n + 2;
+        if (m < n)
+                return -ENOMEM;
+
+        v = strdup(value);
+        if (!v)
+                return -ENOMEM;
+
+        c = realloc_multiply(*l, sizeof(char*), m);
+        if (!c) {
+                free(v);
+                return -ENOMEM;
+        }
+
+        memmove(c+1, c, n * sizeof(char*));
+        c[0] = v;
+        c[n+1] = NULL;
+
+        *l = c;
+        return 0;
+}
+
 char **strv_uniq(char **l) {
         char **i;
 
@@ -781,11 +817,7 @@ char **strv_reverse(char **l) {
                 return l;
 
         for (i = 0; i < n / 2; i++) {
-                char *t;
-
-                t = l[i];
-                l[i] = l[n-1-i];
-                l[n-1-i] = t;
+                SWAP_TWO(l[i], l[n-1-i]);
         }
 
         return l;