patch for mupdf communication from marting

git-svn-id: svn://tug.org/texlive/trunk/Build/source@66539 c570f23f-e606-0410-a88d-b1316a301751

texk/dvisvgm/ChangeLog

@@ -1,3 +1,10 @@
+2023-03-11  Karl Berry  <[email protected]>
+
+	* dvisvgm-src/src/Process.cpp: apply last-minute patch for
+	communication with mupdf, in lieu of importing the whole release.
+	https://github.com/mgieseki/dvisvgm/issues/232
+	https://github.com/mgieseki/dvisvgm/commit/f0ab3d07c942acc1d3fd0d8b94498a355fa92d6c.patch
+
 2023-02-28  Luigi Scarso  <[email protected]>
 
 	* dvisvgm-src/src/ttf/Makefile.am (AM_CXXFLAGS): add ZLIB_INCLUDES,

texk/dvisvgm/dvisvgm-src/src/Process.cpp

@@ -118,10 +118,13 @@ bool Process::run (string *out, const SearchPattern &pattern, PipeFlags flags) {
 	Subprocess subprocess;
 	if (!subprocess.run(_cmd, _paramstr, flags))
 		return false;
+	if (out)
+		out->clear();
 	for (;;) {
 		if (out) {
-			out->clear();
-			subprocess.readFromPipe(*out, pattern);
+			string chunk;
+			subprocess.readFromPipe(chunk, pattern);
+			*out += chunk;
 		}
 		Subprocess::State state = subprocess.state();
 		if (state != Subprocess::State::RUNNING)