fix to make += work with dynamic integer vars like RANDOM

doc/bashref.info

@@ -5754,7 +5754,7 @@ Variables::).
      started.  Assignment to this variable resets the count to the value
      assigned, and the expanded value becomes the value assigned plus
      the number of seconds since the assignment.  The number of seconds
-     at shell invocation and the current time is always determined by
+     at shell invocation and the current time are always determined by
      querying the system clock.  If 'SECONDS' is unset, it loses its
      special properties, even if it is subsequently reset.
 
@@ -12476,77 +12476,77 @@ Node: Special Builtins216717
 Node: Shell Variables217696
 Node: Bourne Shell Variables218133
 Node: Bash Variables220237
-Node: Bash Features253052
-Node: Invoking Bash254065
-Node: Bash Startup Files260078
-Node: Interactive Shells265181
-Node: What is an Interactive Shell?265591
-Node: Is this Shell Interactive?266240
-Node: Interactive Shell Behavior267055
-Node: Bash Conditional Expressions270684
-Node: Shell Arithmetic275326
-Node: Aliases278270
-Node: Arrays280883
-Node: The Directory Stack287130
-Node: Directory Stack Builtins287914
-Node: Controlling the Prompt292174
-Node: The Restricted Shell295139
-Node: Bash POSIX Mode297749
-Node: Shell Compatibility Mode309022
-Node: Job Control317051
-Node: Job Control Basics317511
-Node: Job Control Builtins322513
-Node: Job Control Variables327913
-Node: Command Line Editing329069
-Node: Introduction and Notation330740
-Node: Readline Interaction332363
-Node: Readline Bare Essentials333554
-Node: Readline Movement Commands335337
-Node: Readline Killing Commands336297
-Node: Readline Arguments338215
-Node: Searching339259
-Node: Readline Init File341445
-Node: Readline Init File Syntax342706
-Node: Conditional Init Constructs364194
-Node: Sample Init File368390
-Node: Bindable Readline Commands371514
-Node: Commands For Moving372718
-Node: Commands For History374769
-Node: Commands For Text379763
-Node: Commands For Killing383412
-Node: Numeric Arguments386445
-Node: Commands For Completion387584
-Node: Keyboard Macros391775
-Node: Miscellaneous Commands392462
-Node: Readline vi Mode398401
-Node: Programmable Completion399308
-Node: Programmable Completion Builtins407088
-Node: A Programmable Completion Example417783
-Node: Using History Interactively423030
-Node: Bash History Facilities423714
-Node: Bash History Builtins426719
-Node: History Interaction431727
-Node: Event Designators435347
-Node: Word Designators436701
-Node: Modifiers438461
-Node: Installing Bash440272
-Node: Basic Installation441409
-Node: Compilers and Options445131
-Node: Compiling For Multiple Architectures445872
-Node: Installation Names447565
-Node: Specifying the System Type449674
-Node: Sharing Defaults450390
-Node: Operation Controls451063
-Node: Optional Features452021
-Node: Reporting Bugs463239
-Node: Major Differences From The Bourne Shell464514
-Node: GNU Free Documentation License481364
-Node: Indexes506541
-Node: Builtin Index506995
-Node: Reserved Word Index513822
-Node: Variable Index516270
-Node: Function Index532762
-Node: Concept Index546546
+Node: Bash Features253053
+Node: Invoking Bash254066
+Node: Bash Startup Files260079
+Node: Interactive Shells265182
+Node: What is an Interactive Shell?265592
+Node: Is this Shell Interactive?266241
+Node: Interactive Shell Behavior267056
+Node: Bash Conditional Expressions270685
+Node: Shell Arithmetic275327
+Node: Aliases278271
+Node: Arrays280884
+Node: The Directory Stack287131
+Node: Directory Stack Builtins287915
+Node: Controlling the Prompt292175
+Node: The Restricted Shell295140
+Node: Bash POSIX Mode297750
+Node: Shell Compatibility Mode309023
+Node: Job Control317052
+Node: Job Control Basics317512
+Node: Job Control Builtins322514
+Node: Job Control Variables327914
+Node: Command Line Editing329070
+Node: Introduction and Notation330741
+Node: Readline Interaction332364
+Node: Readline Bare Essentials333555
+Node: Readline Movement Commands335338
+Node: Readline Killing Commands336298
+Node: Readline Arguments338216
+Node: Searching339260
+Node: Readline Init File341446
+Node: Readline Init File Syntax342707
+Node: Conditional Init Constructs364195
+Node: Sample Init File368391
+Node: Bindable Readline Commands371515
+Node: Commands For Moving372719
+Node: Commands For History374770
+Node: Commands For Text379764
+Node: Commands For Killing383413
+Node: Numeric Arguments386446
+Node: Commands For Completion387585
+Node: Keyboard Macros391776
+Node: Miscellaneous Commands392463
+Node: Readline vi Mode398402
+Node: Programmable Completion399309
+Node: Programmable Completion Builtins407089
+Node: A Programmable Completion Example417784
+Node: Using History Interactively423031
+Node: Bash History Facilities423715
+Node: Bash History Builtins426720
+Node: History Interaction431728
+Node: Event Designators435348
+Node: Word Designators436702
+Node: Modifiers438462
+Node: Installing Bash440273
+Node: Basic Installation441410
+Node: Compilers and Options445132
+Node: Compiling For Multiple Architectures445873
+Node: Installation Names447566
+Node: Specifying the System Type449675
+Node: Sharing Defaults450391
+Node: Operation Controls451064
+Node: Optional Features452022
+Node: Reporting Bugs463240
+Node: Major Differences From The Bourne Shell464515
+Node: GNU Free Documentation License481365
+Node: Indexes506542
+Node: Builtin Index506996
+Node: Reserved Word Index513823
+Node: Variable Index516271
+Node: Function Index532763
+Node: Concept Index546547
 
 End Tag Table