fix suspend-output-while-selecting buffer, made size configurable (#816…

…, ~#799)

docs/mintty.1

@@ -1816,6 +1816,13 @@ options, which means they can only be set in config files or using the
 \fBClear selection highlighting on input\fP (ClearSelectionOnInput=true)
 When this is disabled, keyboard input or pasting does not clear selection highlighting.
 
+.TP
+\fBSuspend output while selecting\fP (SuspendWhileSelecting=8080)
+During drag-selects, the user may want the screen to hold still 
+to be selected from. Mintty can suspend processing of terminal output 
+for a while; if the buffer exceeds the size configured with this parameter 
+(in bytes), output is flushed. Setting it to 0 disables the feature.
+
 .TP
 \fBTrim trailing space from selection on copy\fP (TrimSelection=true)
 When this is disabled, trailing space that was written to the terminal 

src/config.c

@@ -159,6 +159,7 @@ const config default_cfg = {
   .suppress_wheel = "",
   .filter_paste = "",
   .input_clears_selection = true,
+  .suspbuf_max = 8080,
   .trim_selection = true,
   .charwidth = 0,
   .emojis = 0,
@@ -390,6 +391,7 @@ options[] = {
   {"SuppressMouseWheel", OPT_STRING, offcfg(suppress_wheel)},
   {"FilterPasteControls", OPT_STRING, offcfg(filter_paste)},
   {"ClearSelectionOnInput", OPT_BOOL, offcfg(input_clears_selection)},
+  {"SuspendWhileSelecting", OPT_INT, offcfg(suspbuf_max)},
   {"TrimSelection", OPT_BOOL, offcfg(trim_selection)},
   {"Charwidth", OPT_CHARWIDTH, offcfg(charwidth)},
   {"Emojis", OPT_EMOJIS, offcfg(emojis)},

src/config.h

@@ -158,6 +158,7 @@ typedef struct {
   string suppress_wheel;
   string filter_paste;
   bool input_clears_selection;
+  int suspbuf_max;
   bool trim_selection;
   char charwidth;
   char emojis;

src/termout.c

@@ -2998,22 +2998,20 @@ void
 term_write(const char *buf, uint len)
 {
  /*
-    During drag-selects, we do not wish to process terminal output,
-    because the user will want the screen to hold still to be selected.
+    During drag-selects, some people do not wish to process terminal output,
+    because the user may want the screen to hold still to be selected.
     Therefore, we maintain a suspend-output-on-selection buffer which 
-    can grow up to a moderate size.
+    can grow up to a configurable size.
   */
-  if (term_selecting()) {
-#define suspmax 88800
-#define suspdelta 888
+  if (term_selecting() && cfg.suspbuf_max > 0) {
     // if buffer size would be exceeded, flush; prevent uint overflow
-    if (len > suspmax - term.suspbuf_pos)
+    if (len > cfg.suspbuf_max - term.suspbuf_pos)
       term_flush();
     // if buffer length does not exceed max size, append output
-    if (len <= suspmax - term.suspbuf_pos) {
+    if (len <= cfg.suspbuf_max - term.suspbuf_pos) {
       // make sure buffer is large enough
       if (term.suspbuf_pos + len > term.suspbuf_size) {
-        term.suspbuf_size += suspdelta;
+        term.suspbuf_size = term.suspbuf_pos + len;
         term.suspbuf = renewn(term.suspbuf, term.suspbuf_size);
       }
       memcpy(term.suspbuf + term.suspbuf_pos, buf, len);

wiki/Changelog.md

@@ -8,6 +8,7 @@ Appearance
   * Option Background== for floating window effect (using desktop wallpaper as background) (#18, ~#666, ~~#501).
 
 Window handling
+  * Fixed suspend-output-while-selecting buffer, size is configurable (#816, ~#799).
   * Consider glyph width for font width determination (#808).
   * Do not start process to construct process list for exit confirmation (~#448).
   * Enhanced taskbar icon grouping behaviour (#784, mintty/wsltty#96, ?#495, ?#420, ??#801).
@@ -16,6 +17,7 @@ Window handling
 
 Configuration
   * AppID supports placeholders for flexible customization of taskbar icon grouping behaviour (#784, mintty/wsltty#96, ?#495, ?#420, ??#801).
+  * Option SuspendWhileSelecting to set the max size of the suspend-output-while-selecting buffer (#816, ~#799).
 
 ### 2.9.3 (4 October 2018) ###