(struct glyph_row): New member extra_line_spacing.

(struct it): New member max_extra_line_spacing.
(MR_PARTIALLY_VISIBLE, MR_PARTIALLY_VISIBLE_AT_TOP)
(MR_PARTIALLY_VISIBLE_AT_BOTTOM): New helper macros.
(MATRIX_ROW_PARTIALLY_VISIBLE_P): Fix to return false if invisible
part of last line is only extra line spacing (so the text on the
line is fully visible). Use helper macros.
Add W arg (to use them).  All callers changed.
(MATRIX_ROW_PARTIALLY_VISIBLE_AT_TOP_P)
(MATRIX_ROW_PARTIALLY_VISIBLE_AT_BOTTOM_P): Use helper macros.

1 files changed, 33 insertions, 9 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index d6c93cb270e..7e8d15d8e8f 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -694,6 +694,10 @@ struct glyph_row
      frames.  It may be < 0 in case of completely invisible rows.  */
   int visible_height;
 
+  /* Extra line spacing added after this row.  Do not consider this
+     in last row when checking if row is fully visible.  */
+  int extra_line_spacing;
+
   /* Hash code.  This hash code is available as soon as the row
      is constructed, i.e. after a call to display_line.  */
   unsigned hash;
@@ -916,22 +920,39 @@ struct glyph_row *matrix_row P_ ((struct glyph_matrix *, int));
 
 #define MATRIX_ROW_DISPLAYS_TEXT_P(ROW) ((ROW)->displays_text_p)
 
+
+/* Helper macros */
+
+#define MR_PARTIALLY_VISIBLE(ROW)       \
+  ((ROW)->height != (ROW)->visible_height)
+
+#define MR_PARTIALLY_VISIBLE_AT_TOP(W, ROW)  \
+  ((ROW)->y < WINDOW_HEADER_LINE_HEIGHT ((W)))
+
+#define MR_PARTIALLY_VISIBLE_AT_BOTTOM(W, ROW)  \
+  (((ROW)->y + (ROW)->height - (ROW)->extra_line_spacing) \
+   > WINDOW_BOX_HEIGHT_NO_MODE_LINE ((W)))
+
 /* Non-zero if ROW is not completely visible in window W.  */
 
-#define MATRIX_ROW_PARTIALLY_VISIBLE_P(ROW)     \
-     ((ROW)->height != (ROW)->visible_height)
+#define MATRIX_ROW_PARTIALLY_VISIBLE_P(W, ROW)          \
+  (MR_PARTIALLY_VISIBLE ((ROW))                         \
+   && (MR_PARTIALLY_VISIBLE_AT_TOP ((W), (ROW))         \
+       || MR_PARTIALLY_VISIBLE_AT_BOTTOM ((W), (ROW))))
+
+
 
 /* Non-zero if ROW is partially visible at the top of window W.  */
 
 #define MATRIX_ROW_PARTIALLY_VISIBLE_AT_TOP_P(W, ROW)           \
-     (MATRIX_ROW_PARTIALLY_VISIBLE_P ((ROW))                    \
-      && (ROW)->y < WINDOW_HEADER_LINE_HEIGHT ((W)))
+  (MR_PARTIALLY_VISIBLE ((ROW))                                 \
+   && MR_PARTIALLY_VISIBLE_AT_TOP ((W), (ROW)))
 
 /* Non-zero if ROW is partially visible at the bottom of window W.  */
 
-#define MATRIX_ROW_PARTIALLY_VISIBLE_AT_BOTTOM_P(W, ROW)                      \
-     (MATRIX_ROW_PARTIALLY_VISIBLE_P ((ROW))                                  \
-      && (ROW)->y + (ROW)->height > WINDOW_BOX_HEIGHT_NO_MODE_LINE ((W)))
+#define MATRIX_ROW_PARTIALLY_VISIBLE_AT_BOTTOM_P(W, ROW)        \
+  (MR_PARTIALLY_VISIBLE ((ROW))                                 \
+   && MR_PARTIALLY_VISIBLE_AT_BOTTOM ((W), (ROW)))
 
 /* Return the bottom Y + 1 of ROW.   */
 
@@ -1990,10 +2011,13 @@ struct it
      line, if the window has one.  */
   int last_visible_y;
 
-  /* Additional space in pixels between lines (for window systems
-     only.)  */
+  /* Default amount of additional space in pixels between lines (for
+     window systems only.)  */
   int extra_line_spacing;
 
+  /* Max extra line spacing added in this row.  */
+  int max_extra_line_spacing;
+
   /* Override font height information for this glyph.
      Used if override_ascent >= 0.  Cleared after this glyph.  */
   int override_ascent, override_descent, override_boff;