Merge branch 'gawk-5.1-stable'

4 files changed, 396 insertions, 335 deletions

diff --git a/doc/ChangeLog b/doc/ChangeLog
index 95515c3b..04bec844 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,6 +1,13 @@
+2022-02-07         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* gawktexi.in (Indirect Calls): Expand discussion of calling
+	built-in functions directly.
+	(POSIX Floating Point Problems): Add a note that the sign of
+	NaN values can vary.
+
 2022-01-05         Arnold D. Robbins     <arnold@skeeve.com>
 
-	* gawktexi.ini (Indirect Calls): Use `the_function' everywhere.
+	* gawktexi.in (Indirect Calls): Use `the_function' everywhere.
 	Thanks to John Naman, <gawker@703n.com> for the report.
 
 2021-12-10         Arnold D. Robbins     <arnold@skeeve.com>
diff --git a/doc/gawk.info b/doc/gawk.info
index e11d3b06..0be3deca 100644
--- a/doc/gawk.info
+++ b/doc/gawk.info
@@ -15577,14 +15577,27 @@ Dynamic Extensions::).  There are some limitations when calling built-in
 functions indirectly, as follows.
 
    * You cannot pass a regular expression constant to a built-in
-     function through an indirect function call.(1)  This applies to the
+     function through an indirect function call.  This applies to the
      'sub()', 'gsub()', 'gensub()', 'match()', 'split()' and
-     'patsplit()' functions.
+     'patsplit()' functions.  However, you can pass a strongly typed
+     regexp constant (*note Strong Regexp Constants::).
 
    * If calling 'sub()' or 'gsub()', you may only pass two arguments,
      since those functions are unusual in that they update their third
      argument.  This means that '$0' will be updated.
 
+   * You cannot indirectly call built-in functions that can take '$0' as
+     a default parameter; you must supply an argument instead.  For
+     example, you must pass an argument to 'length()' if calling it
+     indirectly.
+
+   * Calling a built-in function indirectly with the wrong number of
+     arguments for that function causes a fatal error.  For example,
+     calling 'length()' with two arguments.  These errors are found at
+     runtime instead of when 'gawk' parses your program, since 'gawk'
+     doesn't know until runtime if you have passed the correct number of
+     arguments or not.
+
    'gawk' does its best to make indirect function calls efficient.  For
 example, in the following case:
 
@@ -15593,11 +15606,6 @@ example, in the following case:
 
 'gawk' looks up the actual function to call only once.
 
-   ---------- Footnotes ----------
-
-   (1) This may change in a future version; recheck the documentation
-that comes with your version of 'gawk' to see if it has.
-
 
 File: gawk.info,  Node: Functions Summary,  Prev: Indirect Calls,  Up: Functions
 
@@ -25278,6 +25286,13 @@ described: '+inf', '-inf', '+nan', or '-nan'.  Similarly, in POSIX mode,
 'gawk' prints the result of the system's C 'printf()' function using the
 '%g' format string for the value, whatever that may be.
 
+     NOTE: The sign used for NaN values can vary!  The result depends
+     upon both the underlying system architecture and the underlying
+     library used to format NaN values.  In particular, it's possible to
+     get different results for the same function call depending upon
+     whether or not 'gawk' is running in MPFR mode ('-M') or not.
+     Caveat Emptor!
+
    ---------- Footnotes ----------
 
    (1) You asked for it, you got it.
@@ -39013,325 +39028,324 @@ Ref: Function Caveats-Footnote-1637557
 Node: Return Statement637677
 Node: Dynamic Typing640656
 Node: Indirect Calls641586
-Ref: Indirect Calls-Footnote-1651853
-Node: Functions Summary651981
-Node: Library Functions654686
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-Ref: Library Functions-Footnote-2658436
-Node: Library Names658607
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-Ref: Library Names-Footnote-2662497
-Node: General Functions662583
-Node: Strtonum Function663765
-Node: Assert Function666787
-Node: Round Function670113
-Node: Cliff Random Function671653
-Node: Ordinal Functions672669
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-Ref: Ordinal Functions-Footnote-2675984
-Node: Join Function676194
-Ref: Join Function-Footnote-1677964
-Node: Getlocaltime Function678164
-Node: Readfile Function681906
-Node: Shell Quoting683883
-Node: Isnumeric Function685311
-Node: Data File Management686699
-Node: Filetrans Function687331
-Node: Rewind Function691427
-Node: File Checking693336
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-Node: Empty Files694871
-Node: Ignoring Assigns696850
-Node: Getopt Function698400
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-Node: Passwd Functions713897
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+Node: Non-Unix Installation1257811
+Node: PC Installation1258271
+Node: PC Binary Installation1259109
+Node: PC Compiling1259982
+Node: PC Using1261099
+Node: Cygwin1264652
+Node: MSYS1265876
+Node: VMS Installation1266478
+Node: VMS Compilation1267197
+Ref: VMS Compilation-Footnote-11268426
+Node: VMS Dynamic Extensions1268484
+Node: VMS Installation Details1270169
+Node: VMS Running1272431
+Node: VMS GNV1276710
+Node: Bugs1277424
+Node: Bug definition1278336
+Node: Bug address1281272
+Node: Usenet1284660
+Node: Performance bugs1285849
+Node: Asking for help1288770
+Node: Maintainers1290737
+Node: Other Versions1291931
+Node: Installation summary1300095
+Node: Notes1301459
+Node: Compatibility Mode1302253
+Node: Additions1303035
+Node: Accessing The Source1303960
+Node: Adding Code1305397
+Node: New Ports1311589
+Node: Derived Files1315964
+Ref: Derived Files-Footnote-11321624
+Ref: Derived Files-Footnote-21321659
+Ref: Derived Files-Footnote-31322257
+Node: Future Extensions1322371
+Node: Implementation Limitations1323029
+Node: Extension Design1324239
+Node: Old Extension Problems1325383
+Ref: Old Extension Problems-Footnote-11326901
+Node: Extension New Mechanism Goals1326958
+Ref: Extension New Mechanism Goals-Footnote-11330322
+Node: Extension Other Design Decisions1330511
+Node: Extension Future Growth1332624
+Node: Notes summary1333230
+Node: Basic Concepts1334388
+Node: Basic High Level1335069
+Ref: figure-general-flow1335351
+Ref: figure-process-flow1336037
+Ref: Basic High Level-Footnote-11339339
+Node: Basic Data Typing1339524
+Node: Glossary1342852
+Node: Copying1374739
+Node: GNU Free Documentation License1412282
+Node: Index1437402
 
 End Tag Table
 
diff --git a/doc/gawk.texi b/doc/gawk.texi
index 730208a6..bfd1a00b 100644
--- a/doc/gawk.texi
+++ b/doc/gawk.texi
@@ -22281,16 +22281,28 @@ built-in functions indirectly, as follows.
 @itemize @value{BULLET}
 @item
 You cannot pass a regular expression constant to a built-in function
-through an indirect function call.@footnote{This may change in a future
-version; recheck the documentation that comes with your version of
-@command{gawk} to see if it has.} This applies to the @code{sub()},
+through an indirect function call.  This applies to the @code{sub()},
 @code{gsub()}, @code{gensub()}, @code{match()}, @code{split()} and
-@code{patsplit()} functions.
+@code{patsplit()} functions.  However, you can pass a strongly typed
+regexp constant (@pxref{Strong Regexp Constants}).
 
 @item
 If calling @code{sub()} or @code{gsub()}, you may only pass two arguments,
 since those functions are unusual in that they update their third argument.
 This means that @code{$0} will be updated.
+
+@item
+You cannot indirectly call built-in functions that can take @code{$0} as
+a default parameter; you must supply an argument instead.  For example,
+you must pass an argument to @code{length()} if calling it indirectly.
+
+@item
+Calling a built-in function indirectly with the wrong number of arguments
+for that function causes a fatal error. For example, calling
+@code{length()} with two arguments.  These errors are found at runtime
+instead of when @command{gawk} parses your program, since @command{gawk}
+doesn't know until runtime if you have passed the correct number of
+arguments or not.
 @end itemize
 
 @command{gawk} does its best to make indirect function calls efficient.
@@ -35284,6 +35296,14 @@ Similarly, in POSIX mode, @command{gawk} prints the result of
 the system's C @code{printf()} function using the @code{%g} format string
 for the value, whatever that may be.
 
+@quotation NOTE
+The sign used for NaN values can vary!  The result depends upon both
+the underlying system architecture and the underlying library used to
+format NaN values. In particular, it's possible to get different results
+for the same function call depending upon whether or not @command{gawk}
+is running in MPFR mode (@option{-M}) or not. Caveat Emptor!
+@end quotation
+
 @node Floating point summary
 @section Summary
 
diff --git a/doc/gawktexi.in b/doc/gawktexi.in
index 2a9321bc..66de1068 100644
--- a/doc/gawktexi.in
+++ b/doc/gawktexi.in
@@ -21193,16 +21193,28 @@ built-in functions indirectly, as follows.
 @itemize @value{BULLET}
 @item
 You cannot pass a regular expression constant to a built-in function
-through an indirect function call.@footnote{This may change in a future
-version; recheck the documentation that comes with your version of
-@command{gawk} to see if it has.} This applies to the @code{sub()},
+through an indirect function call.  This applies to the @code{sub()},
 @code{gsub()}, @code{gensub()}, @code{match()}, @code{split()} and
-@code{patsplit()} functions.
+@code{patsplit()} functions.  However, you can pass a strongly typed
+regexp constant (@pxref{Strong Regexp Constants}).
 
 @item
 If calling @code{sub()} or @code{gsub()}, you may only pass two arguments,
 since those functions are unusual in that they update their third argument.
 This means that @code{$0} will be updated.
+
+@item
+You cannot indirectly call built-in functions that can take @code{$0} as
+a default parameter; you must supply an argument instead.  For example,
+you must pass an argument to @code{length()} if calling it indirectly.
+
+@item
+Calling a built-in function indirectly with the wrong number of arguments
+for that function causes a fatal error. For example, calling
+@code{length()} with two arguments.  These errors are found at runtime
+instead of when @command{gawk} parses your program, since @command{gawk}
+doesn't know until runtime if you have passed the correct number of
+arguments or not.
 @end itemize
 
 @command{gawk} does its best to make indirect function calls efficient.
@@ -34127,6 +34139,14 @@ Similarly, in POSIX mode, @command{gawk} prints the result of
 the system's C @code{printf()} function using the @code{%g} format string
 for the value, whatever that may be.
 
+@quotation NOTE
+The sign used for NaN values can vary!  The result depends upon both
+the underlying system architecture and the underlying library used to
+format NaN values. In particular, it's possible to get different results
+for the same function call depending upon whether or not @command{gawk}
+is running in MPFR mode (@option{-M}) or not. Caveat Emptor!
+@end quotation
+
 @node Floating point summary
 @section Summary