5 files changed, 23 insertions, 2 deletions
diff --git a/Build/source/texk/web2c/cwebdir/ChangeLog b/Build/source/texk/web2c/cwebdir/ChangeLog
index 62f30474c33..ea272b92180 100644
--- a/Build/source/texk/web2c/cwebdir/ChangeLog
+++ b/Build/source/texk/web2c/cwebdir/ChangeLog
@@ -1,6 +1,13 @@
 2020-06-07  Andreas Scherer  <https://ascherer.github.io>
 
 	* comm-w2c.ch,
+	* ctang-w2c.ch,
+	* cweav-w2c.ch,
+	* ctwill-w2c.ch: Check accessibility to designated output files.
+
+2020-06-07  Andreas Scherer  <https://ascherer.github.io>
+
+	* comm-w2c.ch,
 	* comm-w2c.h,
 	* ctang-w2c.ch,
 	* cweav-w2c.ch,
diff --git a/Build/source/texk/web2c/cwebdir/comm-w2c.ch b/Build/source/texk/web2c/cwebdir/comm-w2c.ch
index 805d90d6af9..3fe2ac1bf62 100644
--- a/Build/source/texk/web2c/cwebdir/comm-w2c.ch
+++ b/Build/source/texk/web2c/cwebdir/comm-w2c.ch
@@ -869,7 +869,7 @@ fatal(
 @x
   if (*s) printf(s);
 @y
-  if (*s) fputs(s,stdout);
+  if (*s) err_print(s);
 @z
 
 @x
@@ -1129,6 +1129,10 @@ else {
 @ @<Scan arguments and open output files@>=
 scan_args();
 if (program==ctangle) {
+  if ((C_file=fopen(C_file_name,"a"))==NULL)
+    fatal(_("! Cannot open output file "), C_file_name);
+@.Cannot open output file@>
+  else fclose(C_file); /* Test accessability */
   strcpy(check_file_name,C_file_name);
   if(check_file_name[0]!='\0') {
     char *dot_pos=strrchr(check_file_name,'.');
@@ -1140,6 +1144,9 @@ if (program==ctangle) {
 @.Cannot open output file@>
 }
 else {
+  if ((tex_file=fopen(tex_file_name,"a"))==NULL)
+    fatal(_("! Cannot open output file "), tex_file_name);
+  else fclose(tex_file); /* Test accessability */
   strcpy(check_file_name,tex_file_name);
   if(check_file_name[0]!='\0') {
     char *dot_pos=strrchr(check_file_name,'.');
diff --git a/Build/source/texk/web2c/cwebdir/ctang-w2c.ch b/Build/source/texk/web2c/cwebdir/ctang-w2c.ch
index 6bacb8d0982..a137092b111 100644
--- a/Build/source/texk/web2c/cwebdir/ctang-w2c.ch
+++ b/Build/source/texk/web2c/cwebdir/ctang-w2c.ch
@@ -312,9 +312,12 @@ fclose(C_file); C_file=NULL;
 for (an_output_file=end_output_files; an_output_file>cur_out_file;) {
     an_output_file--;
     sprint_section_name(output_file_name,*an_output_file);
+    if ((C_file=fopen(output_file_name,"a"))==NULL)
+      fatal(_("! Cannot open output file "),output_file_name);
+@.Cannot open output file@>
+    else fclose(C_file); /* Test accessability */
     if((C_file=fopen(check_file_name,"wb"))==NULL)
       fatal(_("! Cannot open output file "),check_file_name);
-@.Cannot open output file@>
     if (show_progress) { printf("\n(%s)",output_file_name); update_terminal; }
     cur_line=1;
     stack_ptr=stack+1;
diff --git a/Build/source/texk/web2c/cwebdir/ctwill-w2c.ch b/Build/source/texk/web2c/cwebdir/ctwill-w2c.ch
index 29bb9f093a4..59e0cf6ea76 100644
--- a/Build/source/texk/web2c/cwebdir/ctwill-w2c.ch
+++ b/Build/source/texk/web2c/cwebdir/ctwill-w2c.ch
@@ -349,8 +349,10 @@ char **av@t\2\2@>) /* argument values */
 
 @x
 @d max_scraps 2000 /* number of tokens in \CEE/ texts being parsed */
+@d stack_size 400 /* number of simultaneous output levels */
 @y
 @d max_scraps 10000 /* number of tokens in \CEE/ texts being parsed */
+@d stack_size 2000 /* number of simultaneous output levels */
 @z
 
 @x
diff --git a/Build/source/texk/web2c/cwebdir/cweav-w2c.ch b/Build/source/texk/web2c/cwebdir/cweav-w2c.ch
index fded6e677b5..db419d81db4 100644
--- a/Build/source/texk/web2c/cwebdir/cweav-w2c.ch
+++ b/Build/source/texk/web2c/cwebdir/cweav-w2c.ch
@@ -125,8 +125,10 @@ char **av@t\2\2@>) /* argument values */
 
 @x
 @d max_scraps 2000 /* number of tokens in \CEE/ texts being parsed */
+@d stack_size 400 /* number of simultaneous output levels */
 @y
 @d max_scraps 10000 /* number of tokens in \CEE/ texts being parsed */
+@d stack_size 2000 /* number of simultaneous output levels */
 @z
 
 @x