patch 9.0.1725: cursor pos wrong after concealed text with 'virtualedit'

Problem:    Wrong cursor position when clicking after concealed text
            with 'virtualedit'.
Solution:   Store virtual columns in ScreenCols[] instead of text
            columns, and always use coladvance() when clicking.

This also fixes incorrect curswant when clicking on a TAB, so now
Test_normal_click_on_ctrl_char() asserts the same results as the ones
before patch 9.0.0048.

closes: #12808

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>

src/drawline.c

@@ -1829,7 +1829,6 @@ win_line(
 
     win_line_start(wp, &wlv, FALSE);
 
-    char_u	*prev_ptr = ptr;
     // Repeat for the whole displayed line.
     for (;;)
     {
@@ -2261,9 +2260,9 @@ win_line(
 	    }
 #endif
 
+#ifdef FEAT_SEARCH_EXTRA
 	    if (wlv.n_extra == 0)
 	    {
-#ifdef FEAT_SEARCH_EXTRA
 		// Check for start/end of 'hlsearch' and other matches.
 		// After end, check for start/end of next match.
 		// When another match, have to check for start again.
@@ -2278,10 +2277,8 @@ win_line(
 		// and bad things happen.
 		if (*ptr == NUL)
 		    has_match_conc = 0;
-#endif
-
-		prev_ptr = ptr;
 	    }
+#endif
 
 #ifdef FEAT_DIFF
 	    if (wlv.diff_hlf != (hlf_T)0)
@@ -2356,7 +2353,6 @@ win_line(
 		    // have made it invalid.
 		    line = ml_get_buf(wp->w_buffer, lnum, FALSE);
 		    ptr = line + v;
-		    prev_ptr = ptr;
 # ifdef FEAT_CONCEAL
 		    // no concealing past the end of the line, it interferes
 		    // with line highlighting
@@ -2567,7 +2563,9 @@ win_line(
 #ifdef FEAT_LINEBREAK
 	    int		c0;
 #endif
-	    prev_ptr = ptr;
+#ifdef FEAT_SPELL
+	    char_u	*prev_ptr = ptr;
+#endif
 
 	    // Get a character from the line itself.
 	    c = *ptr;
@@ -3809,7 +3807,7 @@ win_line(
 	    else
 		ScreenAttrs[wlv.off] = wlv.char_attr;
 
-	    ScreenCols[wlv.off] = (colnr_T)(prev_ptr - line);
+	    ScreenCols[wlv.off] = wlv.vcol;
 
 	    if (has_mbyte && (*mb_char2cells)(mb_c) > 1)
 	    {
@@ -3833,7 +3831,7 @@ win_line(
 		if (wlv.tocol == wlv.vcol)
 		    ++wlv.tocol;
 
-		ScreenCols[wlv.off] = (colnr_T)(prev_ptr - line);
+		ScreenCols[wlv.off] = wlv.vcol;
 
 #ifdef FEAT_RIGHTLEFT
 		if (wp->w_p_rl)

src/globals.h

@@ -32,7 +32,7 @@ EXTERN long	Columns INIT(= 80);	// nr of columns in the screen
  * The characters that are currently on the screen are kept in ScreenLines[].
  * It is a single block of characters, the size of the screen plus one line.
  * The attributes for those characters are kept in ScreenAttrs[].
- * The byte offset in the line is kept in ScreenCols[].
+ * The virtual column in the line is kept in ScreenCols[].
  *
  * "LineOffset[n]" is the offset from ScreenLines[] for the start of line 'n'.
  * The same value is used for ScreenLinesUC[], ScreenAttrs[] and ScreenCols[].

src/mouse.c

@@ -2060,7 +2060,7 @@ retnomove:
 	// Only use ScreenCols[] after the window was redrawn.  Mainly matters
 	// for tests, a user would not click before redrawing.
 	// Do not use when 'virtualedit' is active.
-	if (curwin->w_redr_type <= UPD_VALID_NO_UPDATE && !virtual_active())
+	if (curwin->w_redr_type <= UPD_VALID_NO_UPDATE)
 	    col_from_screen = ScreenCols[off];
 #ifdef FEAT_FOLDING
 	// Remember the character under the mouse, it might be a '-' or '+' in
@@ -2098,41 +2098,47 @@ retnomove:
 	    redraw_cmdline = TRUE;	// show visual mode later
     }
 
-    if (col_from_screen >= 0)
+    if (col_from_screen == MAXCOL)
     {
-	// Use the column from ScreenCols[], it is accurate also after
-	// concealed characters.
-	curwin->w_cursor.col = col_from_screen;
-	if (col_from_screen == MAXCOL)
+	// When clicking after end of line, still need to set correct curswant
+	int off_l = LineOffset[prev_row];
+	if (ScreenCols[off_l] < MAXCOL)
 	{
-	    curwin->w_curswant = col_from_screen;
-	    curwin->w_set_curswant = FALSE;	// May still have been TRUE
-	    mouse_past_eol = TRUE;
-	    if (inclusive != NULL)
-		*inclusive = TRUE;
+	    // Binary search to find last char in line
+	    int off_r = off_l + prev_col;
+	    int off_click = off_r;
+	    while (off_l < off_r)
+	    {
+		int off_m = (off_l + off_r + 1) / 2;
+		if (ScreenCols[off_m] < MAXCOL)
+		    off_l = off_m;
+		else
+		    off_r = off_m - 1;
+	    }
+	    col = ScreenCols[off_r] + (off_click - off_r);
 	}
 	else
-	{
-	    curwin->w_set_curswant = TRUE;
-	    if (inclusive != NULL)
-		*inclusive = FALSE;
-	}
-	check_cursor_col();
+	    // Shouldn't normally happen
+	    col = MAXCOL;
     }
-    else
+    else if (col_from_screen >= 0)
     {
-	curwin->w_curswant = col;
-	curwin->w_set_curswant = FALSE;	// May still have been TRUE
-	if (coladvance(col) == FAIL)	// Mouse click beyond end of line
-	{
-	    if (inclusive != NULL)
-		*inclusive = TRUE;
-	    mouse_past_eol = TRUE;
-	}
-	else if (inclusive != NULL)
-	    *inclusive = FALSE;
+	// Use the virtual column from ScreenCols[], it is accurate also after
+	// concealed characters.
+	col = col_from_screen;
     }
 
+    curwin->w_curswant = col;
+    curwin->w_set_curswant = FALSE;	// May still have been TRUE
+    if (coladvance(col) == FAIL)	// Mouse click beyond end of line
+    {
+	if (inclusive != NULL)
+	    *inclusive = TRUE;
+	mouse_past_eol = TRUE;
+    }
+    else if (inclusive != NULL)
+	*inclusive = FALSE;
+
     count = IN_BUFFER;
     if (curwin != old_curwin || curwin->w_cursor.lnum != old_cursor.lnum
 	    || curwin->w_cursor.col != old_cursor.col)

src/testdir/test_conceal.vim

@@ -351,9 +351,55 @@ func Test_conceal_mouse_click()
   call test_setmouse(1, 16)
   call feedkeys("\<LeftMouse>", "tx")
   call assert_equal([0, 1, 20, 0, 20], getcurpos())
+  " click on 'e' of "here" puts cursor there
+  call test_setmouse(1, 19)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 23], getcurpos())
+  " click after end of line puts cursor on 'e' without 'virtualedit'
+  call test_setmouse(1, 20)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 24], getcurpos())
+  call test_setmouse(1, 21)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 25], getcurpos())
+  call test_setmouse(1, 22)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 26], getcurpos())
+  call test_setmouse(1, 31)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 35], getcurpos())
+  call test_setmouse(1, 32)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 36], getcurpos())
+
+  set virtualedit=all
+  " click on 'h' of "here" puts cursor there
+  call test_setmouse(1, 16)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 20, 0, 20], getcurpos())
+  " click on 'e' of "here" puts cursor there
+  call test_setmouse(1, 19)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 23, 0, 23], getcurpos())
+  " click after end of line puts cursor there without 'virtualedit'
+  call test_setmouse(1, 20)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 24, 0, 24], getcurpos())
+  call test_setmouse(1, 21)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 24, 1, 25], getcurpos())
+  call test_setmouse(1, 22)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 24, 2, 26], getcurpos())
+  call test_setmouse(1, 31)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 24, 11, 35], getcurpos())
+  call test_setmouse(1, 32)
+  call feedkeys("\<LeftMouse>", "tx")
+  call assert_equal([0, 1, 24, 12, 36], getcurpos())
 
   bwipe!
-  set mouse&
+  set mouse& virtualedit&
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab

src/testdir/test_normal.vim

@@ -4049,13 +4049,13 @@ func Test_normal_click_on_ctrl_char()
   call assert_equal([0, 1, 1, 0, 1], getcurpos())
   call test_setmouse(1, 2)
   call feedkeys("\<LeftMouse>", 'xt')
-  call assert_equal([0, 1, 2, 0, 8], getcurpos())
+  call assert_equal([0, 1, 2, 0, 2], getcurpos())
   call test_setmouse(1, 3)
   call feedkeys("\<LeftMouse>", 'xt')
-  call assert_equal([0, 1, 2, 0, 8], getcurpos())
+  call assert_equal([0, 1, 2, 0, 3], getcurpos())
   call test_setmouse(1, 7)
   call feedkeys("\<LeftMouse>", 'xt')
-  call assert_equal([0, 1, 2, 0, 8], getcurpos())
+  call assert_equal([0, 1, 2, 0, 7], getcurpos())
   call test_setmouse(1, 8)
   call feedkeys("\<LeftMouse>", 'xt')
   call assert_equal([0, 1, 2, 0, 8], getcurpos())
@@ -4067,13 +4067,13 @@ func Test_normal_click_on_ctrl_char()
   call assert_equal([0, 1, 4, 0, 10], getcurpos())
   call test_setmouse(1, 11)
   call feedkeys("\<LeftMouse>", 'xt')
-  call assert_equal([0, 1, 4, 0, 10], getcurpos())
+  call assert_equal([0, 1, 4, 0, 11], getcurpos())
   call test_setmouse(1, 12)
   call feedkeys("\<LeftMouse>", 'xt')
   call assert_equal([0, 1, 5, 0, 12], getcurpos())
   call test_setmouse(1, 13)
   call feedkeys("\<LeftMouse>", 'xt')
-  call assert_equal([0, 1, 5, 0, v:maxcol], getcurpos())
+  call assert_equal([0, 1, 5, 0, 13], getcurpos())
 
   bwipe!
   let &mouse = save_mouse

src/testdir/test_virtualedit.vim

@@ -586,6 +586,12 @@ func Test_virtualedit_mouse()
   call test_setmouse(1, 9)
   call feedkeys("\<LeftMouse>", "xt")
   call assert_equal([0, 1, 6, 0, 9], getcurpos())
+  call test_setmouse(1, 12)
+  call feedkeys("\<LeftMouse>", "xt")
+  call assert_equal([0, 1, 9, 0, 12], getcurpos())
+  call test_setmouse(1, 13)
+  call feedkeys("\<LeftMouse>", "xt")
+  call assert_equal([0, 1, 10, 0, 13], getcurpos())
   call test_setmouse(1, 15)
   call feedkeys("\<LeftMouse>", "xt")
   call assert_equal([0, 1, 10, 2, 15], getcurpos())

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1725,
 /**/
     1724,
 /**/