bee-cache-inventory: get symlink destination with readlink() if missing

src/bee-cache-inventory.c

@@ -59,6 +59,7 @@ struct item {
     char *type;
     char *filename;
     char *destination;
+    char free_destination;
 };
 
 struct inventory_meta {
@@ -146,6 +147,28 @@ int substitute(char *data, char from, char to)
     return 1;
 }
 
+char *read_symlink(const char *filename)
+{
+    ssize_t ret;
+    char buffer[PATH_MAX + 1] = {0};
+    char *copy;
+
+    ret = readlink(filename, buffer, PATH_MAX);
+
+    if (ret == -1) {
+        fprintf(stderr, "bee-cache-inventory: warning: "
+                        "cannot restore empty symlink destination for file '%s': %m\n", filename);
+        return NULL;
+    }
+
+    copy = strdup(buffer);
+
+    if (!copy)
+        fprintf(stderr, "bee-cache-inventory: read_symlink: strdup: %m\n");
+
+    return copy;
+}
+
 BEE_STATIC_INLINE char *_extract_pattern(struct item *item, char **dest, char *hint, char *pattern, char size, int failok)
 {
     char *p;
@@ -182,12 +205,17 @@ int do_separation(char *line, struct item *item)
     /* get possible symlink destination */
     q = strstr(item->filename, "//");
     if (q) {
+        *q = '\0';
         item->destination = q + 2;
+
         if (!*item->destination) {
-            fprintf (stderr, "bee-cache-inventory: syntax error: empty destination for file '%s'\n", item->filename);
-            return 0;
+            item->destination = read_symlink(item->filename);
+
+            if (!item->destination)
+                item->destination = item->filename;
+            else
+                item->free_destination = 1;
         }
-        *q = '\0';
     }
 
     *(p-6) = 0;
@@ -344,6 +372,9 @@ int inventory_fhfh(FILE *infh, FILE *outfh, struct inventory_meta meta)
 
         print_item(outfh, item, meta);
 
+        if (item.free_destination)
+            /* symlink destination was generated by read_symlink */
+            free(item.destination);
     }
 
     return 1;