Stat full path, allocate enough space

Not stat'ing the full path (just entry->d_name) strangely works on glibc/fedora
but fails on musl/alpine. Stat'ing the full path is the right thing to do,
anyways.

There was a heap corruption in `dirl_find_templ_dir` due not allocating enough
space for the terminating NULL in `path_buf`. This again only showed up in
musl/alpine.

data.c

@@ -55,7 +55,7 @@ data_send_dirlisting(int fd, const struct response *res)
     }
 
     /* entry line */
-    if ((ret = dirl_entry(fd, e[i], &templates))) {
+    if ((ret = dirl_entry(fd, e[i], res, &templates))) {
       goto cleanup;
     }
 

dirl.c

@@ -86,7 +86,7 @@ html_escape(const char* src, char* dst, size_t dst_siz)
 static char*
 dirl_find_templ_dir(const char* start_path)
 {
-  char* path_buf = calloc(sizeof(char), strlen(start_path));
+  char* path_buf = calloc(sizeof(char), strlen(start_path)+1);
   strcat(path_buf, start_path);
 
   if (strlen(path_buf) > 1 && path_buf[strlen(path_buf) - 1] == '/') {
@@ -100,8 +100,8 @@ dirl_find_templ_dir(const char* start_path)
     errno = 0;
     while ((de = readdir(cur))) {
       if (de->d_type == DT_REG) {
-        if (strcmp(DIRL_HEADER, de->d_name) || strcmp(DIRL_ENTRY, de->d_name) ||
-            strcmp(DIRL_FOOTER, de->d_name)) {
+        if (!strcmp(DIRL_HEADER, de->d_name) || !strcmp(DIRL_ENTRY, de->d_name) ||
+            !strcmp(DIRL_FOOTER, de->d_name)) {
           closedir(cur);
           return path_buf;
         }
@@ -182,13 +182,18 @@ dirl_header(int fd, const struct response* res, const struct dirl_templ* templ)
 }
 
 enum status
-dirl_entry(int fd, const struct dirent* entry, const struct dirl_templ* templ)
+dirl_entry(int fd,
+           const struct dirent* entry,
+           const struct response* res,
+           const struct dirl_templ* templ)
 {
   struct stat stat_buf;
-  lstat(entry->d_name, &stat_buf);
+  char* path_buf = calloc(sizeof(char), strlen(res->path)+strlen(entry->d_name));
+  strcat(path_buf, res->path);
+  strcat(path_buf, entry->d_name);
+  lstat(path_buf, &stat_buf);
 
   char* nentry = calloc(sizeof(char), strlen(templ->entry) + 1);
-  //strcat(nentry, templ->entry);
   memcpy(nentry, templ->entry, strlen(templ->entry) + 1);
 
   /* Replace placeholder */

dirl.h

@@ -82,7 +82,7 @@ dirl_header(int, const struct response*, const struct dirl_templ*);
 
 /* Print entry into the response */
 enum status
-dirl_entry(int, const struct dirent*, const struct dirl_templ*);
+dirl_entry(int, const struct dirent*, const struct response*, const struct dirl_templ*);
 
 /* Print footer into the response */
 enum status