[attr_line] shift start position needs to account for erased

Author: tstack

src/base/ansi_scrubber.cc

@@ -465,7 +465,7 @@ scrub_ansi_string(std::string& str, string_attrs_t* sa)
         }
         if (md[1] || md[3] || md[5]) {
             if (sa != nullptr) {
-                shift_string_attrs(*sa, sf.sf_begin, -sf.length());
+                shift_string_attrs(*sa, sf.sf_begin - erased, -sf.length());
                 if (has_attrs) {
                     for (auto tmp_sa_curr = tmp_sa_open;
                          tmp_sa_curr < tmp_sa.size();

src/base/attr_line.cc

@@ -907,7 +907,7 @@ line_range::shift(int32_t start, int32_t amount)
             this->lr_end = std::max(0, this->lr_end + amount);
         }
     } else if (this->lr_end != -1) {
-        if (start <= this->lr_end) {
+        if (start < this->lr_end) {
             if (amount < 0 && amount < (start - this->lr_end)) {
                 this->lr_end = start + amount;
             } else {

test/test_ansi_scrubber.cc

@@ -48,6 +48,18 @@ main(int argc, char* argv[])
 {
     printf("BEGIN test\n");
 
+    {
+        auto input = std::string("\x1b[33mHello\x1b[0m");
+        string_attrs_t sa;
+
+        auto lr = line_range{0, (int) input.size()};
+        sa.emplace_back(lr, SA_ORIGINAL_LINE.value());
+
+        scrub_ansi_string(input, &sa);
+        assert(sa[0].sa_range.lr_end == input.size());
+        assert("Hello" == input);
+    }
+
     {
         auto input = std::string("\0Hello", 6);
         string_attrs_t sa;