1 files changed, 139 insertions, 9 deletions

diff --git a/src/nvim/mouse.c b/src/nvim/mouse.c
index 2f499e477c..887cbde921 100644
--- a/src/nvim/mouse.c
+++ b/src/nvim/mouse.c
@@ -1,11 +1,16 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
 #include <stdbool.h>
 
 #include "nvim/mouse.h"
 #include "nvim/vim.h"
 #include "nvim/ascii.h"
 #include "nvim/window.h"
+#include "nvim/state.h"
 #include "nvim/strings.h"
 #include "nvim/screen.h"
+#include "nvim/syntax.h"
 #include "nvim/ui.h"
 #include "nvim/os_unix.h"
 #include "nvim/fold.h"
@@ -103,12 +108,14 @@ retnomove:
     goto retnomove;                             // ugly goto...
 
   // Remember the character under the mouse, it might be a '-' or '+' in the
-  // fold column.
+  // fold column. NB: only works for ASCII chars!
   if (row >= 0 && row < Rows && col >= 0 && col <= Columns
-      && ScreenLines != NULL)
-    mouse_char = ScreenLines[LineOffset[row] + (unsigned)col];
-  else
+      && default_grid.chars != NULL) {
+    mouse_char = default_grid.chars[default_grid.line_offset[row]
+                                    + (unsigned)col][0];
+  } else {
     mouse_char = ' ';
+  }
 
   old_curwin = curwin;
   old_cursor = curwin->w_cursor;
@@ -119,6 +126,9 @@ retnomove:
 
     // find the window where the row is in
     wp = mouse_find_win(&row, &col);
+    if (wp == NULL) {
+      return IN_UNKNOWN;
+    }
     dragwin = NULL;
     // winpos and height may change in win_enter()!
     if (row >= wp->w_height) {                  // In (or below) status line
@@ -303,9 +313,12 @@ retnomove:
     mouse_past_bottom = true;
   }
 
+  if (!(flags & MOUSE_RELEASED) && which_button == MOUSE_LEFT) {
+    col = mouse_adjust_click(curwin, row, col);
+  }
+
   // Start Visual mode before coladvance(), for when 'sel' != "old"
   if ((flags & MOUSE_MAY_VIS) && !VIsual_active) {
-    check_visual_highlight();
     VIsual = old_cursor;
     VIsual_active = true;
     VIsual_reselect = true;
@@ -417,6 +430,7 @@ bool mouse_comp_pos(win_T *win, int *rowp, int *colp, linenr_T *lnump)
 
 // Find the window at screen position "*rowp" and "*colp".  The positions are
 // updated to become relative to the top-left of the window.
+// Returns NULL when something is wrong.
 win_T *mouse_find_win(int *rowp, int *colp)
 {
   frame_T     *fp;
@@ -440,7 +454,14 @@ win_T *mouse_find_win(int *rowp, int *colp)
       }
     }
   }
-  return fp->fr_win;
+  // When using a timer that closes a window the window might not actually
+  // exist.
+  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+    if (wp == fp->fr_win) {
+      return wp;
+    }
+  }
+  return NULL;
 }
 
 /*
@@ -450,6 +471,7 @@ void setmouse(void)
 {
   int checkfor;
 
+  ui_cursor_shape();
 
   /* be quick when mouse is off */
   if (*p_mouse == NUL)
@@ -469,9 +491,9 @@ void setmouse(void)
     checkfor = MOUSE_NORMAL;        /* assume normal mode */
 
   if (mouse_has(checkfor)) {
-    ui_mouse_on();
+    ui_call_mouse_on();
   } else {
-    ui_mouse_off();
+    ui_call_mouse_off();
   }
 }
 
@@ -515,7 +537,7 @@ static colnr_T scroll_line_len(linenr_T lnum)
   if (*line != NUL) {
     for (;;) {
       int numchar = chartabsize(line, col);
-      mb_ptr_adv(line);
+      MB_PTR_ADV(line);
       if (*line == NUL) {    // don't count the last character
         break;
       }
@@ -597,3 +619,111 @@ bool mouse_scroll_horiz(int dir)
 
   return leftcol_changed();
 }
+
+/// Adjusts the clicked column position when 'conceallevel' > 0
+static int mouse_adjust_click(win_T *wp, int row, int col)
+{
+  if (!(wp->w_p_cole > 0 && curbuf->b_p_smc > 0
+        && wp->w_leftcol < curbuf->b_p_smc && conceal_cursor_line(wp))) {
+    return col;
+  }
+
+  // `col` is the position within the current line that is highlighted by the
+  // cursor without consideration for concealed characters.  The current line is
+  // scanned *up to* `col`, nudging it left or right when concealed characters
+  // are encountered.
+  //
+  // chartabsize() is used to keep track of the virtual column position relative
+  // to the line's bytes.  For example: if col == 9 and the line starts with a
+  // tab that's 8 columns wide, we would want the cursor to be highlighting the
+  // second byte, not the ninth.
+
+  linenr_T lnum = wp->w_cursor.lnum;
+  char_u *line = ml_get(lnum);
+  char_u *ptr = line;
+  char_u *ptr_end;
+  char_u *ptr_row_offset = line;  // Where we begin adjusting `ptr_end`
+
+  // Find the offset where scanning should begin.
+  int offset = wp->w_leftcol;
+  if (row > 0) {
+    offset += row * (wp->w_width - win_col_off(wp) - win_col_off2(wp) -
+                     wp->w_leftcol + wp->w_skipcol);
+  }
+
+  int vcol;
+
+  if (offset) {
+    // Skip everything up to an offset since nvim takes care of displaying the
+    // correct portion of the line when horizontally scrolling.
+    // When 'wrap' is enabled, only the row (of the wrapped line) needs to be
+    // checked for concealed characters.
+    vcol = 0;
+    while (vcol < offset && *ptr != NUL) {
+      vcol += chartabsize(ptr, vcol);
+      ptr += utfc_ptr2len(ptr);
+    }
+
+    ptr_row_offset = ptr;
+  }
+
+  // Align `ptr_end` with `col`
+  vcol = offset;
+  ptr_end = ptr_row_offset;
+  while (vcol < col && *ptr_end != NUL) {
+    vcol += chartabsize(ptr_end, vcol);
+    ptr_end += utfc_ptr2len(ptr_end);
+  }
+
+  int matchid;
+  int prev_matchid;
+  int nudge = 0;
+  int cwidth = 0;
+
+  vcol = offset;
+
+#define incr() nudge++; ptr_end += utfc_ptr2len(ptr_end)
+#define decr() nudge--; ptr_end -= utfc_ptr2len(ptr_end)
+
+  while (ptr < ptr_end && *ptr != NUL) {
+    cwidth = chartabsize(ptr, vcol);
+    vcol += cwidth;
+    if (cwidth > 1 && *ptr == '\t' && nudge > 0) {
+      // A tab will "absorb" any previous adjustments.
+      cwidth = MIN(cwidth, nudge);
+      while (cwidth > 0) {
+        decr();
+        cwidth--;
+      }
+    }
+
+    matchid = syn_get_concealed_id(wp, lnum, (colnr_T)(ptr - line));
+    if (matchid != 0) {
+      if (wp->w_p_cole == 3) {
+        incr();
+      } else {
+        if (!(row > 0 && ptr == ptr_row_offset)
+            && (wp->w_p_cole == 1 || (wp->w_p_cole == 2
+                                      && (lcs_conceal != NUL
+                                          || syn_get_sub_char() != NUL)))) {
+          // At least one placeholder character will be displayed.
+          decr();
+        }
+
+        prev_matchid = matchid;
+
+        while (prev_matchid == matchid && *ptr != NUL) {
+          incr();
+          ptr += utfc_ptr2len(ptr);
+          matchid = syn_get_concealed_id(wp, lnum, (colnr_T)(ptr - line));
+        }
+
+        continue;
+      }
+    }
+
+    ptr += utfc_ptr2len(ptr);
+  }
+
+  return col + nudge;
+}