Fix loading plugin fails with missing directory GH issue #3248 (#3325)

4 files changed, 39 insertions, 15 deletions

diff --git a/src/H5PLint.c b/src/H5PLint.c
index ff0be4e..6fbae7c 100644
--- a/src/H5PLint.c
+++ b/src/H5PLint.c
@@ -248,16 +248,22 @@ H5PL_load(H5PL_type_t type, H5PL_key_t key)
 
     /* Search in the table of already loaded plugin libraries */
     if (H5PL__find_plugin_in_cache(&search_params, &found, &plugin_info) < 0)
-        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in plugin cache  failed")
+        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in plugin cache failed")
 
     /* If not found, try iterating through the path table to find an appropriate plugin */
     if (!found)
         if (H5PL__find_plugin_in_path_table(&search_params, &found, &plugin_info) < 0)
-            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in path table failed")
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL,
+                        "can't find plugin in the paths either set by HDF5_PLUGIN_PATH, or default location, "
+                        "or set by H5PLxxx functions")
 
     /* Set the return value we found the plugin */
     if (found)
         ret_value = plugin_info;
+    else
+        HGOTO_ERROR(H5E_PLUGIN, H5E_NOTFOUND, NULL,
+                    "can't find plugin. Check either HDF5_PLUGIN_PATH, default location, "
+                    "or path set by H5PLxxx functions")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -268,9 +274,29 @@ done:
  *
  * Purpose:     Opens a plugin.
  *
- *              The success parameter will be set to TRUE and the plugin_info
- *              parameter will be filled in on success. Otherwise, they
- *              will be FALSE and NULL, respectively.
+ *              `path` specifies the path to the plugin library file.
+ *
+ *              `type` specifies the type of plugin being searched for and
+ *              will be used to verify that a loaded plugin matches the
+ *              type requested. H5PL_TYPE_NONE may be passed, in which case
+ *              no plugin type verification is performed. This is most
+ *              useful when iterating over available plugins without regard
+ *              to their types.
+ *
+ *              `key` specifies the information that will be used to find a
+ *              specific plugin. For filter plugins, this is typically an integer
+ *              identifier. After a plugin has been opened, this information will
+ *              be compared against the relevant information provided by the
+ *              plugin to ensure that the plugin is a match. If
+ *              H5PL_TYPE_NONE is provided for `type`, then `key` should be
+ *              NULL.
+ *
+ *              On successful open of a plugin, the `success` parameter
+ *              will be set to TRUE and the `plugin_type` and `plugin_info`
+ *              parameters will be filled appropriately. On failure, the
+ *              `success` parameter will be set to FALSE, the `plugin_type`
+ *              parameter will be set to H5PL_TYPE_ERROR and the
+ *              `plugin_info` parameter will be set to NULL.
  *
  * Return:      SUCCEED/FAIL
  *
diff --git a/src/H5PLpath.c b/src/H5PLpath.c
index fc66448..f9626f5 100644
--- a/src/H5PLpath.c
+++ b/src/H5PLpath.c
@@ -583,8 +583,7 @@ H5PL__find_plugin_in_path_table(const H5PL_search_params_t *search_params, hbool
 
         /* Search for the plugin in this path */
         if (H5PL__find_plugin_in_path(search_params, found, H5PL_paths_g[u], plugin_info) < 0)
-            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "search in path %s encountered an error",
-                        H5PL_paths_g[u])
+            HERROR(H5E_PLUGIN, H5E_CANTGET, "search in path %s encountered an error", H5PL_paths_g[u]);
 
         /* Break out if found */
         if (*found) {
@@ -636,7 +635,8 @@ H5PL__find_plugin_in_path(const H5PL_search_params_t *search_params, hbool_t *fo
 
     /* Open the directory */
     if (!(dirp = HDopendir(dir)))
-        HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, FAIL, "can't open directory: %s", dir)
+        HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, FAIL, "can't open directory (%s). Please verify its existence",
+                    dir)
 
     /* Iterate through all entries in the directory */
     while (NULL != (dp = HDreaddir(dirp))) {
@@ -714,7 +714,7 @@ H5PL__find_plugin_in_path(const H5PL_search_params_t *search_params, hbool_t *fo
     *found = FALSE;
 
     /* Specify a file mask. *.* = We want everything! */
-    HDsprintf(service, "%s\\*.dll", dir);
+    HDsnprintf(service, sizeof(service), "%s\\*.dll", dir);
     if ((hFind = FindFirstFileA(service, &fdFile)) == INVALID_HANDLE_VALUE)
         HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, FAIL, "can't open directory")
 
diff --git a/src/H5PLplugin_cache.c b/src/H5PLplugin_cache.c
index 1d267a2..b48229c 100644
--- a/src/H5PLplugin_cache.c
+++ b/src/H5PLplugin_cache.c
@@ -286,9 +286,7 @@ H5PL__find_plugin_in_cache(const H5PL_search_params_t *search_params, hbool_t *f
 
             /* No need to continue processing */
             break;
-
-        } /* end if */
-
+        }
     } /* end for */
 
 done:
diff --git a/src/H5PLpublic.h b/src/H5PLpublic.h
index f5332e6..31d4e4f 100644
--- a/src/H5PLpublic.h
+++ b/src/H5PLpublic.h
@@ -91,9 +91,9 @@ H5_DLL herr_t H5PLset_loading_state(unsigned int plugin_control_mask);
  * \brief Queries the loadability of dynamic plugin types
  *
  * \param[out] plugin_control_mask List of dynamic plugin types that are enabled or disabled.\n
- *                                 A plugin bit set to 0 (zero) indicates that that the dynamic plugin type is
+ *                                 A plugin bit set to 0 (zero) indicates that the dynamic plugin type is
  *                                 disabled.\n
- *                                 A plugin bit set to 1 (one) indicates that that the dynamic plugin type is
+ *                                 A plugin bit set to 1 (one) indicates that the dynamic plugin type is
  *                                 enabled.\n
  *                                 If the value of \p plugin_control_mask is negative, all dynamic plugin
  *                                 types are enabled.\n
@@ -101,7 +101,7 @@ H5_DLL herr_t H5PLset_loading_state(unsigned int plugin_control_mask);
  *                                 are disabled.
  * \return \herr_t
  *
- * \details H5PLget_loading_state() retrieves the bitmask that controls whether a certain type of plugins
+ * \details H5PLget_loading_state() retrieves the bitmask that controls whether a certain type of plugin
  *          (e.g.: filters, VOL drivers) will be loaded by the HDF5 library.
  *
  *          Bit positions allocated to date are specified in \ref H5PL_type_t as follows: