From f3f3f806243efcd15d8000b96119608dd79163ab Mon Sep 17 00:00:00 2001
From: Andrew Vos <andrew.vos@gmail.com>
Date: Mon, 16 Nov 2020 16:02:13 +0000
Subject: [PATCH] Ignore indent when completing lines

When doing line completion, we previously used to not complete the line
if it had different indent to the potential completion.

This commit changes the behaviour to ignore indentation when completing lines.
---
 src/insert_completer.cc          | 17 +++++++++++------
 test/compose/line-completion/cmd |  1 +
 test/compose/line-completion/in  |  4 ++++
 test/compose/line-completion/out |  4 ++++
 4 files changed, 20 insertions(+), 6 deletions(-)
 create mode 100644 test/compose/line-completion/cmd
 create mode 100644 test/compose/line-completion/in
 create mode 100644 test/compose/line-completion/out

diff --git a/src/insert_completer.cc b/src/insert_completer.cc
index ca6b08a1..43a4fc61 100644
--- a/src/insert_completer.cc
+++ b/src/insert_completer.cc
@@ -348,7 +348,8 @@ InsertCompletion complete_line(const SelectionList& sels,
     const ColumnCount tabstop = options["tabstop"].get<int>();
     const ColumnCount column = get_column(buffer, tabstop, cursor_pos);
 
-    StringView prefix = buffer[cursor_pos.line].substr(0_byte, cursor_pos.column);
+    StringView prefix = trim_indent(buffer[cursor_pos.line].substr(0_byte, cursor_pos.column));
+    BufferCoord replace_begin = buffer.advance(cursor_pos, -prefix.length());
     InsertCompletion::CandidateList candidates;
 
     auto add_candidates = [&](const Buffer& buf) {
@@ -356,12 +357,16 @@ InsertCompletion complete_line(const SelectionList& sels,
         {
             if (buf.name() == buffer.name() && l == cursor_pos.line)
                 continue;
-            const StringView line = buf[l];
+
+            const StringView line = trim_indent(buf[l]);
+
+            if (line.length() == 0)
+              continue;
+
             if (prefix == line.substr(0_byte, prefix.length()))
             {
-                StringView candidate = line.substr(0_byte, line.length()-1);
-                candidates.push_back({candidate.str(), "",
-                                      {expand_tabs(candidate, tabstop, column), {}}});
+                StringView candidate = trim_indent(line.substr(0_byte, line.length()));
+                candidates.push_back({candidate.str(), "", {expand_tabs(candidate, tabstop, column), {}} });
                 // perf: it's unlikely the user intends to search among >10 candidates anyway
                 if (candidates.size() == 100)
                     break;
@@ -384,7 +389,7 @@ InsertCompletion complete_line(const SelectionList& sels,
         return {};
     std::sort(candidates.begin(), candidates.end());
     candidates.erase(std::unique(candidates.begin(), candidates.end()), candidates.end());
-    return { std::move(candidates), cursor_pos.line, cursor_pos, buffer.timestamp() };
+    return { std::move(candidates), replace_begin, cursor_pos, buffer.timestamp() };
 }
 
 }
diff --git a/test/compose/line-completion/cmd b/test/compose/line-completion/cmd
new file mode 100644
index 00000000..46a2bfdd
--- /dev/null
+++ b/test/compose/line-completion/cmd
@@ -0,0 +1 @@
+gjA<c-x>l<c-n><c-n><esc>
diff --git a/test/compose/line-completion/in b/test/compose/line-completion/in
new file mode 100644
index 00000000..d7d4c490
--- /dev/null
+++ b/test/compose/line-completion/in
@@ -0,0 +1,4 @@
+            w111111
+
+    w222222
+                          
diff --git a/test/compose/line-completion/out b/test/compose/line-completion/out
new file mode 100644
index 00000000..398d9af4
--- /dev/null
+++ b/test/compose/line-completion/out
@@ -0,0 +1,4 @@
+            w111111
+
+    w222222
+                          w222222