Fix crash with .env files that are exactly 159 bytes long (#3369)

* Fix crash with .env files that are exactly 158 bytes and a newline character

* Update env_loader.zig

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/src/env_loader.zig b/src/env_loader.zig
index 7d506a04e..8a3838101 100644
--- a/src/env_loader.zig
+++ b/src/env_loader.zig
@@ -884,18 +884,21 @@ pub const Loader = struct {
         defer file.close();
 
         const stat = try file.stat();
-        if (stat.size == 0) {
+        const end = stat.size;
+
+        if (end == 0) {
             @field(this, base) = logger.Source.initPathString(base, "");
             return;
         }
 
-        var buf = try this.allocator.allocSentinel(u8, stat.size, 0);
+        var buf = try this.allocator.alloc(u8, end + 1);
         errdefer this.allocator.free(buf);
-        var contents = try file.readAll(buf);
+        const amount_read = try file.readAll(buf[0..end]);
+
+        // The null byte here is mostly for debugging purposes.
+        buf[end] = 0;
 
-        // always sentinel
-        buf.ptr[contents + 1] = 0;
-        const source = logger.Source.initPathString(base, buf.ptr[0..contents :0]);
+        const source = logger.Source.initPathString(base, buf[0..amount_read]);
 
         Parser.parse(
             &source,