Use JULIA_DEPOT_PATH and JULIA_LOAD_PATH from the environment

When these environment variables are set, use them.

Author: kpamnany

src/julia_init.c

@@ -46,19 +46,39 @@ void set_depot_load_path(const char *root_dir) {
 #else
     char *julia_share_subdir = "/share/julia";
 #endif
-    char *share_dir =
-        calloc(sizeof(char), strlen(root_dir) + strlen(julia_share_subdir) + 1);
-    strcat(share_dir, root_dir);
-    strcat(share_dir, julia_share_subdir);
+    int share_path_len = strlen(root_dir) + strlen(julia_share_subdir) + 1;
+
+    char *curr_depot_path = getenv("JULIA_DEPOT_PATH");
+    int curr_depot_path_len = curr_depot_path == NULL ? 0 : strlen(curr_depot_path);
+    int new_depot_path_len = curr_depot_path_len + 1 + share_path_len;
+    char *new_depot_path = calloc(sizeof (char), new_depot_path_len);
+    if (curr_depot_path_len > 0) {
+        strcat(new_depot_path, curr_depot_path);
+        strcat(new_depot_path, ":");
+    }
+    strcat(new_depot_path, root_dir);
+    strcat(new_depot_path, julia_share_subdir);
+
+    char *curr_load_path = getenv("JULIA_LOAD_PATH");
+    int curr_load_path_len = curr_load_path == NULL ? 0 : strlen(curr_load_path);
+    int new_load_path_len = curr_load_path_len + 1 + share_path_len;
+    char *new_load_path = calloc(sizeof (char), new_load_path_len);
+    if (curr_load_path_len > 0) {
+        strcat(new_load_path, curr_load_path);
+        strcat(new_load_path, ":");
+    }
+    strcat(new_load_path, root_dir);
+    strcat(new_load_path, julia_share_subdir);
 
 #ifdef _WIN32
-    _putenv_s("JULIA_DEPOT_PATH", share_dir);
-    _putenv_s("JULIA_LOAD_PATH", share_dir);
+    _putenv_s("JULIA_DEPOT_PATH", new_depot_path);
+    _putenv_s("JULIA_LOAD_PATH", new_load_path);
 #else
-    setenv("JULIA_DEPOT_PATH", share_dir, 1);
-    setenv("JULIA_LOAD_PATH", share_dir, 1);
+    setenv("JULIA_DEPOT_PATH", new_depot_path, 1);
+    setenv("JULIA_LOAD_PATH", new_load_path, 1);
 #endif
-    free(share_dir);
+    free(new_load_path);
+    free(new_depot_path);
 }
 
 void init_julia(int argc, char **argv) {