config: need to dupe filepath for diagnostics

Fixes #2800

The source string with the filepath is not guaranteed to exist beyond
the lifetime of the parse operation. We must copy it.

3 files changed, 11 insertions, 8 deletions

diff --git a/src/cli/args.zig b/src/cli/args.zig
index 3e378f347..454ca360e 100644
--- a/src/cli/args.zig
+++ b/src/cli/args.zig
@@ -104,7 +104,7 @@ pub fn parse(
             try dst._diagnostics.append(arena_alloc, .{
                 .key = try arena_alloc.dupeZ(u8, arg),
                 .message = "invalid field",
-                .location = diags.Location.fromIter(iter),
+                .location = try diags.Location.fromIter(iter, arena_alloc),
             });
 
             continue;
@@ -145,7 +145,7 @@ pub fn parse(
             try dst._diagnostics.append(arena_alloc, .{
                 .key = try arena_alloc.dupeZ(u8, key),
                 .message = message,
-                .location = diags.Location.fromIter(iter),
+                .location = try diags.Location.fromIter(iter, arena_alloc),
             });
         };
     }
@@ -1140,7 +1140,7 @@ pub fn ArgsIterator(comptime Iterator: type) type {
         }
 
         /// Returns a location for a diagnostic message.
-        pub fn location(self: *const Self) ?diags.Location {
+        pub fn location(self: *const Self, _: Allocator) error{}!?diags.Location {
             return .{ .cli = self.index };
         }
     };
@@ -1262,12 +1262,15 @@ pub fn LineIterator(comptime ReaderType: type) type {
         }
 
         /// Returns a location for a diagnostic message.
-        pub fn location(self: *const Self) ?diags.Location {
+        pub fn location(
+            self: *const Self,
+            alloc: Allocator,
+        ) Allocator.Error!?diags.Location {
             // If we have no filepath then we have no location.
             if (self.filepath.len == 0) return null;
 
             return .{ .file = .{
-                .path = self.filepath,
+                .path = try alloc.dupe(u8, self.filepath),
                 .line = self.line,
             } };
         }
diff --git a/src/cli/diagnostics.zig b/src/cli/diagnostics.zig
index 8090684fd..40fed3001 100644
--- a/src/cli/diagnostics.zig
+++ b/src/cli/diagnostics.zig
@@ -56,7 +56,7 @@ pub const Location = union(enum) {
 
     pub const Key = @typeInfo(Location).Union.tag_type.?;
 
-    pub fn fromIter(iter: anytype) Location {
+    pub fn fromIter(iter: anytype, alloc: Allocator) Allocator.Error!Location {
         const Iter = t: {
             const T = @TypeOf(iter);
             break :t switch (@typeInfo(T)) {
@@ -67,7 +67,7 @@ pub const Location = union(enum) {
         };
 
         if (!@hasDecl(Iter, "location")) return .none;
-        return iter.location() orelse .none;
+        return (try iter.location(alloc)) orelse .none;
     }
 
     pub fn clone(self: *const Location, alloc: Allocator) Allocator.Error!Location {
diff --git a/src/config/Config.zig b/src/config/Config.zig
index 2dc732752..a3bc79099 100644
--- a/src/config/Config.zig
+++ b/src/config/Config.zig
@@ -2988,7 +2988,7 @@ pub fn parseManuallyHook(
 
         if (command.items.len == 0) {
             try self._diagnostics.append(alloc, .{
-                .location = cli.Location.fromIter(iter),
+                .location = try cli.Location.fromIter(iter, alloc),
                 .message = try std.fmt.allocPrintZ(
                     alloc,
                     "missing command after {s}",