5 files changed, 20 insertions, 14 deletions
diff --git a/Build/source/texk/web2c/cwebboot.cin b/Build/source/texk/web2c/cwebboot.cin
index 4e1eda44868..f455693f118 100644
--- a/Build/source/texk/web2c/cwebboot.cin
+++ b/Build/source/texk/web2c/cwebboot.cin
@@ -23,7 +23,7 @@
 #include <string.h>  
 
 /*:3*//*89:*/
-#line 710 "cwebdir/comm-w2c.ch"
+#line 709 "cwebdir/comm-w2c.ch"
 
 #if HAVE_GETTEXT
 #include <locale.h>  
@@ -34,7 +34,7 @@
 #endif
 
 /*:89*//*91:*/
-#line 757 "cwebdir/comm-w2c.ch"
+#line 756 "cwebdir/comm-w2c.ch"
 
 typedef bool boolean;
 #define HAVE_BOOLEAN
@@ -44,7 +44,7 @@ typedef bool boolean;
 #include <lib/lib.h>  
 
 /*:91*//*94:*/
-#line 796 "cwebdir/comm-w2c.ch"
+#line 795 "cwebdir/comm-w2c.ch"
 
 #define CWEB
 #include "help.h" 
@@ -482,7 +482,7 @@ static int section_name_cmp(char**,int,name_pointer);
 static void scan_args(void);
 
 /*:75*//*96:*/
-#line 809 "cwebdir/comm-w2c.ch"
+#line 808 "cwebdir/comm-w2c.ch"
 
 static void cb_usage(const_string str);
 static void cb_usagehelp(const_string*message,const_string bug_email);
@@ -515,7 +515,7 @@ for(h= hash;h<=hash_end;*h++= NULL);
 #line 78 "cwebdir/comm-w2c.ch"
 
 /*92:*/
-#line 771 "cwebdir/comm-w2c.ch"
+#line 770 "cwebdir/comm-w2c.ch"
 
 kpse_set_program_name(argv[0],"cweb");
 
@@ -524,7 +524,7 @@ kpse_set_program_name(argv[0],"cweb");
 
 #line 85 "cwebdir/comm-w2c.ch"
 /*90:*/
-#line 719 "cwebdir/comm-w2c.ch"
+#line 718 "cwebdir/comm-w2c.ch"
 
 setlocale(LC_MESSAGES,setlocale(LC_CTYPE,""));
 texmf_locale= kpse_var_expand("${TEXMFLOCALEDIR}");
@@ -1427,7 +1427,7 @@ if((**(++argv)=='-'||**argv=='+')&&*(*argv+1))/*80:*/
 if(strcmp("-help",*argv)==0||strcmp("--help",*argv)==0)
 
 /*95:*/
-#line 800 "cwebdir/comm-w2c.ch"
+#line 799 "cwebdir/comm-w2c.ch"
 
 cb_usagehelp(program==ctangle?CTANGLEHELP:
 program==cweave?CWEAVEHELP:CTWILLHELP,NULL);
@@ -1439,7 +1439,7 @@ program==cweave?CWEAVEHELP:CTWILLHELP,NULL);
 if(strcmp("-version",*argv)==0||strcmp("--version",*argv)==0)
 
 /*98:*/
-#line 847 "cwebdir/comm-w2c.ch"
+#line 846 "cwebdir/comm-w2c.ch"
 
 printversionandexit(cb_banner,
 program==ctwill?"Donald E. Knuth":"Silvio Levy and Donald E. Knuth",
@@ -1618,7 +1618,7 @@ cb_usage(program==ctangle?"ctangle":program==cweave?"cweave":"ctwill");
 
 #line 496 "cwebdir/comm-w2c.ch"
 /*:76*//*97:*/
-#line 813 "cwebdir/comm-w2c.ch"
+#line 812 "cwebdir/comm-w2c.ch"
 
 static void cb_usage(const_string str)
 {
@@ -1651,7 +1651,7 @@ history= spotless;exit(wrap_up());
 }
 
 /*:97*//*99:*/
-#line 855 "cwebdir/comm-w2c.ch"
+#line 854 "cwebdir/comm-w2c.ch"
 
 void cb_show_banner(void)
 {
diff --git a/Build/source/texk/web2c/cwebdir/ChangeLog b/Build/source/texk/web2c/cwebdir/ChangeLog
index 9fd5e609075..d873c6244fe 100644
--- a/Build/source/texk/web2c/cwebdir/ChangeLog
+++ b/Build/source/texk/web2c/cwebdir/ChangeLog
@@ -1,5 +1,11 @@
 2021-02-24  Andreas Scherer  <https://ascherer.github.io>
 
+	* common.w,
+	* ctangle.w,
+	* cweave.w: Fine print for single '@' characters in TeX text.
+
+2021-02-24  Andreas Scherer  <https://ascherer.github.io>
+
 	* cweave.w: Fix output format when 'tracing @2'.
 
 2021-02-23  Andreas Scherer  <https://ascherer.github.io>
diff --git a/Build/source/texk/web2c/cwebdir/common.w b/Build/source/texk/web2c/cwebdir/common.w
index 85188f4e405..2b90275437d 100644
--- a/Build/source/texk/web2c/cwebdir/common.w
+++ b/Build/source/texk/web2c/cwebdir/common.w
@@ -289,7 +289,7 @@ prepares to read the next line from |change_file|.
 
 When a match is found, the current section is marked as changed unless
 the first line after the \.{@@x} and after the \.{@@y} both start with
-either |'@@*'| or |'@@ '| (possibly preceded by whitespace).
+either `\.{@@*}' or `\.{@@\ }' (possibly preceded by whitespace).
 
 This procedure is called only when |buffer<limit|, i.e., when the
 current line is nonempty.
diff --git a/Build/source/texk/web2c/cwebdir/ctangle.w b/Build/source/texk/web2c/cwebdir/ctangle.w
index 590e90ef1da..0c5bd413282 100644
--- a/Build/source/texk/web2c/cwebdir/ctangle.w
+++ b/Build/source/texk/web2c/cwebdir/ctangle.w
@@ -1236,7 +1236,7 @@ case identifier: a=id_lookup(id_first,id_loc,0)-name_dir;
   app_repl(a % 0400); break;
 case section_name: if (t!=section_name) goto done;
   else {
-    @<Was an `@@' missed here?@>@;
+    @<Was an `\.{@@}' missed here?@>@;
     a=cur_section_name-name_dir;
     app_repl((a / 0400)+0250);
     app_repl(a % 0400);
@@ -1263,7 +1263,7 @@ case definition: case format_code: case begin_C: if (t!=section_name) goto done;
   }
 case new_section: goto done;
 
-@ @<Was an `@@'...@>= {
+@ @<Was an `\.{@@}'...@>= {
   char *try_loc=loc;
   while (*try_loc==' ' && try_loc<limit) try_loc++;
   if (*try_loc=='+' && try_loc<limit) try_loc++;
diff --git a/Build/source/texk/web2c/cwebdir/cweave.w b/Build/source/texk/web2c/cwebdir/cweave.w
index 36180a5321f..27ec6ca75a3 100644
--- a/Build/source/texk/web2c/cwebdir/cweave.w
+++ b/Build/source/texk/web2c/cwebdir/cweave.w
@@ -598,7 +598,7 @@ skip_limbo(void) {
   while(true) {
     if (loc>limit && get_line()==false) return;
     *(limit+1)='@@';
-    while (*loc!='@@') loc++; /* look for '@@', then skip two chars */
+    while (*loc!='@@') loc++; /* look for `\.{@@}', then skip two chars */
     if (loc++ <=limit) { int c=ccode[(eight_bits)*loc++];
       if (c==new_section) return;
       if (c==noop) skip_restricted();