Use custom basename(3) to avoid ptr reuse

As http://man7.org/linux/man-pages/man3/basename.3.html says:

  These functions may return pointers to
  statically allocated memory which may be
  overwritten by subsequent calls.

So we just reimplement a safer one.

Fixes #253.

src/onion/log.c

@@ -29,6 +29,7 @@
 #include <stdlib.h>
 #include <syslog.h>
 #include <unistd.h>
+#include "utils.h"
 
 #ifdef HAVE_PTHREADS
 #include <pthread.h>
@@ -135,7 +136,7 @@ void onion_log_stderr(onion_log_level level, const char *filename, int lineno,
     }
   }
 
-  filename = basename((char *)filename);
+  filename = onion_basename((char *)filename);
 
 #ifdef __DEBUG__
   if ((level == O_DEBUG0) && (!debug0 || !strstr(debug0, filename))) {

src/onion/utils.h

@@ -30,16 +30,42 @@ extern "C" {
 // In the HTTP RFC whitespace is always these characters
 // and is not locale independent, we'll need this when
 // parsing
-  static int __attribute__ ((unused)) is_space(char c) {
-    if (c == '\t' || c == '\n' || c == '\r' || c == ' ')
-      return 1;
-    return 0;
-  } static int __attribute__ ((unused)) is_alnum(char c) {
-    if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z')
-        || (c >= 'a' && c <= 'z'))
-      return 1;
-    return 0;
+static int __attribute__ ((unused)) is_space(char c) {
+  if (c == '\t' || c == '\n' || c == '\r' || c == ' ')
+    return 1;
+  return 0;
+}
+static int __attribute__ ((unused)) is_alnum(char c) {
+  if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z')
+      || (c >= 'a' && c <= 'z'))
+    return 1;
+  return 0;
+}
+
+/**
+ * @short Reimplementation of basename(3)
+ *
+ * basename(3) has some problems on some platforms that reuse the returned pointer,
+ * this version always returns an pointer inside *path.
+ *
+ * As http://man7.org/linux/man-pages/man3/basename.3.html says: These functions
+ * may return pointers to statically allocated memory which may be overwritten
+ * by subsequent calls.
+ *
+ * This implementation does not return "." on NULL data, but NULL.
+ */
+static __attribute__ ((unused)) const char * onion_basename(const char *path){
+  if (!path)
+    return path;
+  const char *basename = path;
+  while (*path) {
+    if (*path == '/')
+      basename = path + 1; // Maybe last part? I keep it just in case.
+    path++;
   }
+  return basename;
+}
+
 
 #ifdef __cplusplus
 }

tests/04-prerecorded/prerecorded.c

@@ -38,6 +38,7 @@
 #include <onion/log.h>
 #include <onion/dict.h>
 #include <onion/block.h>
+#include <onion/utils.h>
 
 #include "../ctest.h"
 #include "../01-internal/buffer_listen_point.h"
@@ -93,7 +94,7 @@ onion_connection_status allinfo_handler(void *data, onion_request * req,
 
 /**
  * @short Performs regexec on each line of string.
- * 
+ *
  * As regexec cant use ^$ to find the line limits, but the string limits, we split the string to make
  * the find of ^ and $ on each line.
  */
@@ -131,7 +132,7 @@ void prerecorded(const char *oscript, int do_r) {
     END_LOCAL();
     return;
   }
-  const char *script = basename((char *)oscript);
+  const char *script = onion_basename((char *)oscript);
 
   onion_listen_point *listen_point = onion_get_listen_point(server, 0);
   onion_request *req = onion_request_new(listen_point);
@@ -260,7 +261,7 @@ void prerecorded(const char *oscript, int do_r) {
 
 /**
  * @short Executes each script file passed as argument.
- * 
+ *
  * Optionally a -r sets the new lines to \r\n. It takes care of not changing content types.
  */
 int main(int argc, char **argv) {

tools/opack/opack.c

@@ -29,6 +29,7 @@
 #include <dirent.h>
 #include <sys/stat.h>
 #include <onion/mime.h>
+#include <onion/utils.h>
 
 #include "../common/updateassets.h"
 
@@ -91,7 +92,7 @@ int main(int argc, char **argv) {
       struct stat st;
       stat(argv[i], &st);
       if (S_ISDIR(st.st_mode)) {
-        parse_directory(basename(argv[1]), argv[i], outfd, assets);
+        parse_directory(onion_basename(argv[1]), argv[i], outfd, assets);
       } else {
         parse_file("", argv[i], outfd, assets);
       }

tools/otemplate/otemplate.c

@@ -32,6 +32,7 @@
 
 #include "onion/log.h"
 #include "onion/block.h"
+#include "onion/utils.h"
 #include "list.h"
 #include "parser.h"
 #include "tags.h"
@@ -181,7 +182,7 @@ int work(const char *infilename, const char *outfilename,
   status.infilename = infilename;
   char tmp2[256];
   strncpy(tmp2, infilename, sizeof(tmp2) - 1);
-  const char *tname = basename(tmp2);
+  const char *tname = onion_basename(tmp2);
   ONION_DEBUG("Create init function on top, tname %s", tname);
   status.blocks_init = function_new(&status, "%s_blocks_init", tname);
   status.blocks_init->signature = "onion_dict *context";

tools/otemplate/tag_builtins.c

@@ -33,6 +33,7 @@
 #include <onion/log.h>
 #include <onion/codecs.h>
 #include <onion/block.h>
+#include <onion/utils.h>
 
 #include "functions.h"
 #include "parser.h"
@@ -211,7 +212,7 @@ void tag_block(parser_status * st, list * l) {
   assert(strlen(st->infilename) < sizeof(tmp));
   strncpy(tmp, st->infilename, sizeof(tmp) - 1);
   function_data *d =
-      function_new(st, "%s__block_%s", basename(tmp), block_name);
+      function_new(st, "%s__block_%s", onion_basename(tmp), block_name);
   function_add_code_f(st->blocks_init,
                       "  if (!onion_dict_get(context, \"__block_%s__\"))\n"
                       "    onion_dict_add(context, \"__block_%s__\", %s, 0);\n",