From c10b3017d6479bbfeceb3a466b6b2c04aa24d9b8 Mon Sep 17 00:00:00 2001
From: ridiculousfish <corydoras@ridiculousfish.com>
Date: Fri, 30 Mar 2012 11:16:24 -0700
Subject: [PATCH] Improve autosuggesting of cd command

---
 highlight.cpp | 24 ++++++++++++++++++------
 reader.cpp    | 15 ++++++++-------
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/highlight.cpp b/highlight.cpp
index 02b084ec1..3f4cde855 100644
--- a/highlight.cpp
+++ b/highlight.cpp
@@ -533,15 +533,15 @@ static int has_expand_reserved( const wchar_t *str )
 	return 0;
 }
 
+/* Attempts to suggest a completion for a command we handle specially, like 'cd'. Returns true if we recognized the command (even if we couldn't think of a suggestion for it) */
 bool autosuggest_suggest_special(const wcstring &str, const wcstring &working_directory, wcstring &outString) {
     if (str.empty())
         return false;
     
     wcstring cmd;
-    bool had_cmd = false;
+    bool had_cmd = false, recognized_cmd = false;
     
     wcstring suggestion;
-    bool suggestionOK = false;
     
     tokenizer tok;
 	for( tok_init( &tok, str.c_str(), TOK_SQUASH_ERRORS );
@@ -556,12 +556,22 @@ bool autosuggest_suggest_special(const wcstring &str, const wcstring &working_di
 			{
 				if( had_cmd )
 				{
-					if( cmd == L"cd" )
+                    recognized_cmd = (cmd == L"cd");
+					if( recognized_cmd )
 					{
                         wcstring dir = tok_last( &tok );
                         wcstring suggested_path;
                         if (is_potential_path(dir, &suggested_path, true /* require directory */)) {
-                            suggestionOK = true;
+                            /* suggested_path needs to actually have dir as a prefix (perhaps with different case). Handle stuff like ./ */
+                            bool wants_dot_slash = string_prefixes_string(L"./", dir);
+                            bool has_dot_slash = string_prefixes_string(L"./", suggested_path);
+                            
+                            if (wants_dot_slash && ! has_dot_slash) {
+                                suggested_path.insert(0, L"./");
+                            } else if (! wants_dot_slash && has_dot_slash) {
+                                suggested_path.erase(0, 2);
+                            }
+                            
                             suggestion = str;
                             suggestion.erase(tok_get_pos(&tok));
                             suggestion.append(suggested_path);
@@ -668,9 +678,11 @@ bool autosuggest_suggest_special(const wcstring &str, const wcstring &working_di
     }
     tok_destroy( &tok );
     
-    if (suggestionOK)
+    if (recognized_cmd) {
         outString.swap(suggestion);
-    return suggestionOK;
+    }
+    
+    return recognized_cmd;
 }
 
 bool autosuggest_handle_special(const wcstring &str, const wcstring &working_directory, bool *outSuggestionOK) {
diff --git a/reader.cpp b/reader.cpp
index bde0bcb1e..5bf7cebb4 100644
--- a/reader.cpp
+++ b/reader.cpp
@@ -1249,6 +1249,7 @@ struct autosuggestion_context_t {
     int threaded_autosuggest(void) {
         ASSERT_IS_BACKGROUND_THREAD();
         
+        /* If the main thread has moved on, skip all the work */
         if (generation_count != s_generation_count) {
             return 0;
         }
@@ -1279,6 +1280,13 @@ struct autosuggestion_context_t {
             }
         }
         
+        /* Try handling a special command like cd */
+        wcstring special_suggestion;
+        if (autosuggest_suggest_special(search_string, working_directory, special_suggestion)) {
+            this->autosuggestion = special_suggestion;
+            return 1;
+        }
+        
         /* Try normal completions */
         std::vector<completion_t> completions;
         complete(search_string, completions, COMPLETE_AUTOSUGGEST, &this->commands_to_load);
@@ -1303,13 +1311,6 @@ struct autosuggestion_context_t {
             return 1;
         }
         
-        /* Since we didn't find a suggestion from history, try other means */
-        wcstring special_suggestion;
-        if (autosuggest_suggest_special(search_string, working_directory, special_suggestion)) {
-            this->autosuggestion = special_suggestion;
-            return 1;
-        }
-        
         return 0;
     }
 };