A ThemeFile that fails names its file: "theme file /x/mine.zon: file not found", not "theme file: file not found"

The read and parse failures come back after the write, often from a
relative name resolved against the config directory, so which file was
missing or bad was left to guess. They now carry the resolved path,
its middle cut when long.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 24 insertions, 5 deletions

diff --git a/src/colors.zig b/src/colors.zig
index 8d541c13..b75cdc3d 100644
--- a/src/colors.zig
+++ b/src/colors.zig
@@ -759,7 +759,16 @@ pub fn themeFileRequest(p: *const Pardes, generation: u32) ?ThemeFileRequest {
 
 pub fn failThemeFile(p: *Pardes, generation: u32, err: anyerror) void {
     const request = themeFileRequest(p, generation) orelse return;
-    p.reportError(request.pane, "theme file", err);
+    themeFileError(p, request, err);
+}
+
+/// A theme file's failure, said with its path: `theme file x.zon: file
+/// not found`, not which file left to guess.
+fn themeFileError(p: *Pardes, request: ThemeFileRequest, err: anyerror) void {
+    var said: [300]u8 = undefined;
+    var cut: [200]u8 = undefined;
+    const path = @import("ninep/tree.zig").fitErr(request.path, &cut);
+    p.reportError(request.pane, std.fmt.bufPrint(&said, "theme file {s}", .{path}) catch "theme file", err);
 }
 
 pub fn loadThemeFile(p: *Pardes, generation: u32, bytes: []const u8, animate: bool) bool {
@@ -767,23 +776,23 @@ pub fn loadThemeFile(p: *Pardes, generation: u32, bytes: []const u8, animate: bo
     @setEvalBranchQuota(10000);
     const request = themeFileRequest(p, generation) orelse return false;
     if (bytes.len > 1024 * 1024) {
-        p.reportError(request.pane, "theme file", error.ThemeFileTooLarge);
+        themeFileError(p, request, error.ThemeFileTooLarge);
         return false;
     }
     const source = p.gpa.dupeZ(u8, bytes) catch |err| {
-        p.reportError(request.pane, "theme file", err);
+        themeFileError(p, request, err);
         return false;
     };
     defer p.gpa.free(source);
     var diagnostics: std.zon.parse.Diagnostics = .{};
     defer diagnostics.deinit(p.gpa);
     const parsed = std.zon.parse.fromSliceAlloc(Theme, p.gpa, source, &diagnostics, .{}) catch |err| {
-        p.reportError(request.pane, "theme file", err);
+        themeFileError(p, request, err);
         return false;
     };
     if (parsed.name.len == 0 or parsed.name.len > 255) {
         std.zon.parse.free(p.gpa, parsed);
-        p.reportError(request.pane, "theme file", error.InvalidThemeName);
+        themeFileError(p, request, error.InvalidThemeName);
         return false;
     }
 
@@ -912,6 +921,16 @@ pub fn setThemeIndex(p: *Pardes, index: usize) void {
     invalidateThemeDependentRasters(p);
 }
 
+test "a theme file that cannot be read is named in the failure" {
+    if (platform == .web) return;
+    const p = try Pardes.init(std.testing.allocator, .{ .tty_only = true });
+    defer p.deinit();
+    requestThemeFile(p, 0, "/nowhere/mine.zon");
+    failThemeFile(p, p.theme_file_generation, error.FileNotFound);
+    const pane = p.panes[0].?;
+    try std.testing.expect(std.mem.indexOf(u8, pane.msg[0..pane.msg_len], "theme file /nowhere/mine.zon: ") != null);
+}
+
 test "ThemeFile parses ZON atomically and Theme returns to the compiled ring" {
     if (platform == .web) return;
     const p = try Pardes.init(std.testing.allocator, .{