From ecb2da1e271aa0daa6dd2ed4c6658d59347020e6 Mon Sep 17 00:00:00 2001
From: Dan Davison <dandavison7@gmail.com>
Date: Thu, 20 Aug 2020 20:30:14 -0400
Subject: Interpret `line-numbers = false` in gitconfig as no line numbers at
 all (#296)

Fixes #292
---
 src/options/option_value.rs |  7 +++++++
 src/options/set.rs          | 29 ++++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

(limited to 'src/options')

diff --git a/src/options/option_value.rs b/src/options/option_value.rs
index cbe5b383..d569f676 100644
--- a/src/options/option_value.rs
+++ b/src/options/option_value.rs
@@ -55,6 +55,13 @@ impl From<OptionValue> for Option<String> {
     fn from(value: OptionValue) -> Self {
         match value {
             OptionValue::OptionString(value) => value,
+            // HACK: See the comment in options::set::compute_line_numbers_mode(). That function
+            // deliberately reads what is normally a boolean value ('line-numbers') as a string.
+            // However options::get::get_option_value() can fall through to obtaining the value
+            // from builtin_features, in which case an OptionValue::Boolean will be encountered.
+            // See the comment in options::set::compute_line_numbers_mode() and docstring of
+            // options::get::get_option_value().
+            OptionValue::Boolean(_) => None,
             _ => delta_unreachable("Error converting OptionValue to Option<String>."),
         }
     }
diff --git a/src/options/set.rs b/src/options/set.rs
index 150246c9..b8ea10a7 100644
--- a/src/options/set.rs
+++ b/src/options/set.rs
@@ -16,7 +16,7 @@ use crate::features;
 use crate::git_config;
 use crate::git_config_entry::{self, GitConfigEntry};
 use crate::options::option_value::{OptionValue, ProvenancedOptionValue};
-use crate::options::theme;
+use crate::options::{self, theme};
 
 macro_rules! set_options {
 	([$( $field_ident:ident ),* ],
@@ -183,6 +183,8 @@ pub fn set_options(
 
     opt.computed.inspect_raw_lines =
         cli::InspectRawLines::from_str(&opt.inspect_raw_lines).unwrap();
+    opt.computed.line_numbers_mode =
+        compute_line_numbers_mode(opt, &builtin_features, git_config, &option_names);
     opt.computed.paging_mode = parse_paging_mode(&opt.paging_mode);
 
     // --color-only is used for interactive.diffFilter (git add -p) and side-by-side cannot be used
@@ -192,6 +194,31 @@ pub fn set_options(
     }
 }
 
+fn compute_line_numbers_mode(
+    opt: &cli::Opt,
+    builtin_features: &HashMap<String, features::BuiltinFeature>,
+    git_config: &mut Option<git_config::GitConfig>,
+    option_names: &HashMap<&str, &str>,
+) -> cli::LineNumbersMode {
+    // line-numbers is in general treated as a boolean value. We read it as a string here in order
+    // to interpret an explicit "false" (as opposed to merely absence) as meaning "Do not show any
+    // line numbers; not even the first line number of the hunk".
+    let line_numbers_string_value: Option<Option<String>> = options::get::get_option_value(
+        option_names["line-numbers"],
+        builtin_features,
+        opt,
+        git_config,
+    );
+    match (
+        line_numbers_string_value.as_ref().map(|val| val.as_deref()),
+        opt.line_numbers,
+    ) {
+        (Some(Some("false")), _) => cli::LineNumbersMode::None,
+        (_, true) => cli::LineNumbersMode::Full,
+        (_, false) => cli::LineNumbersMode::First,
+    }
+}
+
 #[allow(non_snake_case)]
 fn set__light__dark__syntax_theme__options(
     opt: &mut cli::Opt,
-- 
cgit v1.2.3