Read $GDBHISTSIZE instead of $HISTSIZE

The HISTSIZE environment variable is generally expected to be read by
shells, not by applications.  Some distros for example globally export
HISTSIZE in /etc/profile -- with the intention that it only affects
shells -- and by doing so it renders useless GDB's own mechanism for
setting the history size via .gdbinit.  Also, annoyances may arise when
HISTSIZE is not interpreted the same way by the shell and by GDB, e.g.
PR gdb/16999.  That can always be fixed on a shell-by-shell basis but it
may be impossible to be consistent with the behavior of all shells at
once.  Finally it just makes sense to not confound shell environment
variables with application environment variables.

gdb/ChangeLog:

	* NEWS: Mention that GDBHISTSIZE is read instead of HISTSIZE.
	* top.c (init_history): Read from GDBHISTSIZE instead of
	HISTSIZE.
	(init_main): Refer to GDBHISTSIZE instead of HISTSIZE.

gdb/doc/ChangeLog:

	* gdb.texinfo (Command History): Replace occurrences of HISTSIZE
	with GDBHISTSIZE.

gdb/testsuite/ChangeLog:

	* gdb.base/gdbinit-history.exp: Replace occurrences of HISTSIZE
	with GDBHISTSIZE.
	* gdb.base/readline.exp: Likewise.

3 files changed, 16 insertions, 10 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 65c5579..abb0677 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-06-17  Patrick Palka  <patrick@parcs.ath.cx>
+
+	* gdb.base/gdbinit-history.exp: Replace occurrences of HISTSIZE
+	with GDBHISTSIZE.
+	* gdb.base/readline.exp: Likewise.
+
 2015-06-17  Yao Qi  <yao.qi@linaro.org>
 
 	* lib/gdb.exp (get_build_id): Move braces and "else" to the same
diff --git a/gdb/testsuite/gdb.base/gdbinit-history.exp b/gdb/testsuite/gdb.base/gdbinit-history.exp
index 8c4f4ca..7bdce5f 100644
--- a/gdb/testsuite/gdb.base/gdbinit-history.exp
+++ b/gdb/testsuite/gdb.base/gdbinit-history.exp
@@ -31,10 +31,10 @@ proc test_gdbinit_history_setting { home size } {
 
     set env(HOME) "$srcdir/$subdir/$home"
 
-    # The HISTSIZE environment variable takes precedence over whatever
+    # The GDBHISTSIZE environment variable takes precedence over whatever
     # history size is set in .gdbinit.  Make sure the former is not
     # set.
-    unset -nocomplain env(HISTSIZE)
+    unset -nocomplain env(GDBHISTSIZE)
 
     set saved_internal_gdbflags $INTERNAL_GDBFLAGS
     set INTERNAL_GDBFLAGS [string map {"-nx" ""} $INTERNAL_GDBFLAGS]
@@ -66,10 +66,10 @@ proc test_no_truncation_of_unlimited_history_file { } {
 
     array set old_env [array get env]
 
-    # The HISTSIZE environment variable takes precedence over whatever
+    # The GDBHISTSIZE environment variable takes precedence over whatever
     # history size is set in .gdbinit.  Make sure the former is not
     # set.
-    unset -nocomplain env(HISTSIZE)
+    unset -nocomplain env(GDBHISTSIZE)
 
     set saved_internal_gdbflags $INTERNAL_GDBFLAGS
 
diff --git a/gdb/testsuite/gdb.base/readline.exp b/gdb/testsuite/gdb.base/readline.exp
index c444285..f0490a2 100644
--- a/gdb/testsuite/gdb.base/readline.exp
+++ b/gdb/testsuite/gdb.base/readline.exp
@@ -185,11 +185,11 @@ gdb_test_multiple "if 1 > 0\n\033\[A\033\[A\nend" $msg {
 if [info exists env(GDBHISTFILE)] {
     set old_gdbhistfile $env(GDBHISTFILE)
 }
-if [info exists env(HISTSIZE)] {
-    set old_histsize $env(HISTSIZE)
+if [info exists env(GDBHISTSIZE)] {
+    set old_gdbhistsize $env(GDBHISTSIZE)
 }
 set env(GDBHISTFILE) "${srcdir}/${subdir}/gdb_history"
-set env(HISTSIZE) "10"
+set env(GDBHISTSIZE) "10"
 
 gdb_exit
 gdb_start
@@ -207,10 +207,10 @@ if [info exists old_gdbhistfile] {
 } else {
     unset env(GDBHISTFILE)
 }
-if [info exists old_histsize] {
-    set env(HISTSIZE) $old_histsize
+if [info exists old_gdbhistsize] {
+    set env(GDBHISTSIZE) $old_gdbhistsize
 } else {
-    unset env(HISTSIZE)
+    unset env(GDBHISTSIZE)
 }
 set timeout $oldtimeout1