minor documentation update on SIGINT handling

CWRU/CWRU.chlog

@@ -2310,3 +2310,17 @@ doc/bashref.texi
 
 doc/{mkposix,mkinst,mkrbash},doc/Makefile.in
 	- changes to allow scripts to be run outside the source directory
+
+				   10/18
+				   -----
+subst.c
+	- patsub_replacement: controls whether pattern substitution expands `&'
+	  in the replacement string. Initialized to 1 by default
+
+				   10/19
+				   -----
+doc/{bash.1,bashref.texi}
+	- document bash's WCE SIGINT behavior when job control is not enabled
+	  and the shell receives a SIGINT while waiting for the foreground
+	  command to complete. Added at Red Hat's request. A complete
+	  discussion is at https://www.cons.org/cracauer/sigint.html

doc/bash.1

@@ -5,12 +5,12 @@
 .\"	Case Western Reserve University
 .\"	chet.ramey@case.edu
 .\"
-.\"	Last Change: Fri Oct  8 14:10:30 EDT 2021
+.\"	Last Change: Tue Oct 19 11:34:57 EDT 2021
 .\"
 .\" bash_builtins, strip all but Built-Ins section
 .if \n(zZ=1 .ig zZ
 .if \n(zY=1 .ig zY
-.TH BASH 1 "2021 October 8" "GNU Bash 5.1"
+.TH BASH 1 "2021 October 19" "GNU Bash 5.1"
 .\"
 .\" There's some problem with having a `@'
 .\" in a tagged paragraph with the BSD man macros.
@@ -5214,6 +5214,63 @@ When \fBbash\fP is waiting for an asynchronous command via the \fBwait\fP
 builtin, the reception of a signal for which a trap has been set will
 cause the \fBwait\fP builtin to return immediately with an exit status
 greater than 128, immediately after which the trap is executed.
+.PP
+When job control is not enabled, and \fBbash\fP is waiting for a foreground
+command to complete, the shell receives keyboard-generated signals
+such as
+.SM
+.B SIGINT
+(usually generated by \fB^C\fP) that users commonly intend to send
+to that command.
+This happens because the shell and the command are in the
+same process group as the terminal, and \fB^C\fP sends
+.SM
+.B SIGINT
+to all processes in that process group.
+.PP
+When \fBbash\fP is running without job control enabled and receives 
+.SM
+.B SIGINT
+while waiting for a foreground command, it waits until that foreground
+command terminates and then decides what to do about the
+.SM
+.BR SIGINT :
+.IP 1.
+If the command terminates due to the
+.SM
+.BR SIGINT ,
+\fBbash\fP concludes
+that the user meant to end the entire script, and acts on the
+.SM
+.B SIGINT
+(e.g., by running a
+.SM
+.B SIGINT
+trap or exiting itself);
+.IP 2.
+If the command does not terminate due to
+.SM
+.BR SIGINT ,
+the program handled the
+.SM
+.B SIGINT
+itself and did not treat it as a fatal signal.
+In that case, \fBbash\fP does not treat
+.SM
+.B SIGINT
+as a fatal signal, either, instead assuming that the
+.SM
+.B SIGINT
+was used as part of the program's normal operation
+(e.g., emacs uses it to abort editing
+commands) or deliberately discarded.
+However, \fBbash\fP will run any
+trap set on
+.SM
+.BR SIGINT ,
+as it does with any other trapped signal it
+receives while it is waiting for the foreground command to
+complete, for compatibility.
 .SH "JOB CONTROL"
 .I Job control
 refers to the ability to selectively stop (\fIsuspend\fP)
@@ -10131,6 +10188,8 @@ history is enabled, as described above under
 .B compat43
 .TP 8
 .B compat44
+.TP 8
+.B compat50
 .PD
 These control aspects of the shell's compatibility mode
 (see

doc/bashref.texi

@@ -3549,6 +3549,37 @@ which a trap has been set will cause the @code{wait} builtin to return
 immediately with an exit status greater than 128, immediately after
 which the trap is executed.
 
+When job control is not enabled, and Bash is waiting for a foreground
+command to complete, the shell receives keyboard-generated signals
+such as @code{SIGINT} (usually generated by @samp{^C}) that users
+commonly intend to send to that command.
+This happens because the shell and the command are in the same process
+group as the terminal, and @samp{^C} sends @code{SIGINT} to all processes
+in that process group.
+See @ref{Job Control}, for a more in-depth discussion of process groups.
+
+When Bash is running without job control enabled and receives @code{SIGINT}
+while waiting for a foreground command, it waits until that foreground
+command terminates and then decides what to do about the @code{SIGINT}:
+
+@enumerate
+@item
+If the command terminates due to the @code{SIGINT}, Bash concludes
+that the user meant to end the entire script, and acts on the
+@code{SIGINT} (e.g., by running a @code{SIGINT} trap or exiting itself);
+
+@item
+If the pipeline does not terminate due to @code{SIGINT}, the program
+handled the @code{SIGINT} itself and did not treat it as a fatal signal.
+In that case, Bash does not treat @code{SIGINT} as a fatal signal,
+either, instead assuming that the @code{SIGINT} was used as part of the
+program's normal operation (e.g., @command{emacs} uses it to abort editing
+commands) or deliberately discarded. However, Bash will run any
+trap set on @code{SIGINT}, as it does with any other trapped signal it
+receives while it is waiting for the foreground command to
+complete, for compatibility.
+@end enumerate
+
 @node Shell Scripts
 @section Shell Scripts
 @cindex shell script

doc/version.texi

@@ -2,10 +2,10 @@
 Copyright (C) 1988-2021 Free Software Foundation, Inc.
 @end ignore
 
-@set LASTCHANGE Fri Oct 15 15:24:19 EDT 2021
+@set LASTCHANGE Tue Oct 19 11:34:34 EDT 2021
 
 @set EDITION 5.1
 @set VERSION 5.1
 
-@set UPDATED 15 October 2021
+@set UPDATED 19 October 2021
 @set UPDATED-MONTH October 2021

subst.c

@@ -187,6 +187,10 @@ int allow_null_glob_expansion;
 /* Non-zero means to throw an error when globbing fails to match anything. */
 int fail_glob_expansion;
 
+/* If non-zero, perform `&' substitution on the replacement string in the
+   pattern substitution word expansion. */
+int patsub_replacement = 1;
+
 /* Extern functions and variables from different files. */
 extern struct fd_bitmap *current_fds_to_close;
 extern int wordexp_only;
@@ -8680,7 +8684,7 @@ parameter_brace_patsub (varname, value, ind, patsub, quoted, pflags, flags)
 	 consistently. The replacement string already undergoes quote removal
 	 above, so users need to make sure any desired backslash makes it
 	 through that. */
-      if (rep && *rep && shouldexp_replacement (rep))
+      if (patsub_replacement && rep && *rep && shouldexp_replacement (rep))
 	mflags |= MATCH_EXPREP;
 
     }

tests/RUN-ONE-TEST

@@ -1,4 +1,4 @@
-BUILD_DIR=/usr/local/build/bash/bash-current
+BUILD_DIR=/usr/local/build/chet/bash/bash-current
 THIS_SH=$BUILD_DIR/bash
 PATH=$PATH:$BUILD_DIR