patch 8.2.1220: memory access error when dragging a popup windowv8.2.1220

Problem:    memory access error when dragging a popup window over a buffer
            with folding.
Solution:   Avoid going over the end of the cache. (closes #6438)

4 files changed, 53 insertions, 9 deletions

diff --git a/src/testdir/dumps/Test_popupwin_term_01.dump b/src/testdir/dumps/Test_popupwin_term_01.dump
index 473c991c86..50818c15b9 100644
--- a/src/testdir/dumps/Test_popupwin_term_01.dump
+++ b/src/testdir/dumps/Test_popupwin_term_01.dump
@@ -3,8 +3,14 @@
 @34|╔+0#0000001#ffd7ff255|═@3|╗| +0#0000000#ffffff0@34
 @34|║+0#0000001#ffd7ff255|1@3|║| +0#0000000#ffffff0@34
 |!+0#ffffff16#00e0003|/|b|i|n|/|s|h| |[|r|u|n@1|i|n|g|]| @15|║+0#0000001#ffd7ff255|2@3|║| +0#ffffff16#00e0003@34
-> +0#0000000#ffffff0@33|╚+0#0000001#ffd7ff255|═@3|⇲| +0#0000000#ffffff0@34
-|~+0#4040ff13&| @73
-|~| @73
-|[+3#0000000&|N|o| |N|a|m|e|]| @65
+>++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@14|╚+0#0000001#ffd7ff255|═@3|⇲|-+0#0000e05#a8a8a8255@34
+|1+0#0000000#ffffff0@1| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|2+0#0000000#ffffff0|3| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|3+0#0000000#ffffff0|5| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|4+0#0000000#ffffff0|7| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|[+3#0000000#ffffff0|N|o| |N|a|m|e|]| |[|+|]| @61
 | +0&&@74
diff --git a/src/testdir/dumps/Test_popupwin_term_02.dump b/src/testdir/dumps/Test_popupwin_term_02.dump
index afa330f326..160834aa5d 100644
--- a/src/testdir/dumps/Test_popupwin_term_02.dump
+++ b/src/testdir/dumps/Test_popupwin_term_02.dump
@@ -3,8 +3,14 @@
 @14|╔+0#0000001#ffd7ff255|═@3|╗| +0#0000000#ffffff0@54
 @14|║+0#0000001#ffd7ff255|1@3|║| +0#0000000#ffffff0@54
 |!+0#ffffff16#00e0003|/|b|i|n|/|s|h| |[|r|u|n@1|║+0#0000001#ffd7ff255|2@3|║| +0#ffffff16#00e0003@54
-> +0#0000000#ffffff0@13|╚+0#0000001#ffd7ff255|═@3|⇲| +0#0000000#ffffff0@54
-|~+0#4040ff13&| @73
-|~| @73
-|[+3#0000000&|N|o| |N|a|m|e|]| @65
-|:+0&&|c|a|l@1| |D|r|a|g|i|t|(|)| @60
+>++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |╚+0#0000001#ffd7ff255|═@3|⇲|-+0#0000e05#a8a8a8255@54
+|1+0#0000000#ffffff0@1| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|2+0#0000000#ffffff0|3| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|3+0#0000000#ffffff0|5| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|4+0#0000000#ffffff0|7| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|[+3#0000000#ffffff0|N|o| |N|a|m|e|]| |[|+|]| @61
+|:+0&&|c|a|l@1| |D|r|a|g|i|t|L|e|f|t|(|)| @56
diff --git a/src/testdir/dumps/Test_popupwin_term_03.dump b/src/testdir/dumps/Test_popupwin_term_03.dump
new file mode 100644
index 0000000000..0632ee8e8d
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_term_03.dump
@@ -0,0 +1,16 @@
+|v+0&#ffffff0|i|m|>| @70
+@75
+@75
+@75
+|!+0#ffffff16#00e0003|/|b|i|n|/|s|h| |[|r|u|n@1|i|n|g|]| @56
+>++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|1+0#0000000#ffffff0@1| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|2+0#0000000#ffffff0|3| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|3+0#0000000#ffffff0|5| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@14|╔+0#0000001#ffd7ff255|═@3|╗|-+0#0000e05#a8a8a8255@34
+|4+0#0000000#ffffff0|7| @31|║+0#0000001#ffd7ff255|1@3|║| +0#0000000#ffffff0@34
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@14|║+0#0000001#ffd7ff255|2@3|║|-+0#0000e05#a8a8a8255@34
+|[+3#0000000#ffffff0|N|o| |N|a|m|e|]| |[|+|]| @20|╚+0#0000001#ffd7ff255|═@3|⇲| +3#0000000#ffffff0@34
+|:+0&&|c|a|l@1| |D|r|a|g|i|t|D|o|w|n|(|)| @56
diff --git a/src/testdir/dumps/Test_popupwin_term_04.dump b/src/testdir/dumps/Test_popupwin_term_04.dump
new file mode 100644
index 0000000000..1345b75bb7
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_term_04.dump
@@ -0,0 +1,16 @@
+|v+0&#ffffff0|i|m|>| @70
+@75
+@75
+@75
+|!+0#ffffff16#00e0003|/|b|i|n|/|s|h| |[|r|u|n@1|i|n|g|]| @56
+>++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|1+0#0000000#ffffff0@1| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|2+0#0000000#ffffff0|3| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |f|o|l|d| |-@55
+|3+0#0000000#ffffff0|5| @72
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |╔+0#0000001#ffd7ff255|═@3|╗|-+0#0000e05#a8a8a8255@54
+|4+0#0000000#ffffff0|7| @11|║+0#0000001#ffd7ff255|1@3|║| +0#0000000#ffffff0@54
+|++0#0000e05#a8a8a8255|-@1| |1@1| |l|i|n|e|s|:| |║+0#0000001#ffd7ff255|2@3|║|-+0#0000e05#a8a8a8255@54
+|[+3#0000000#ffffff0|N|o| |N|a|m|e|]| |[|+|]| |╚+0#0000001#ffd7ff255|═@3|⇲| +3#0000000#ffffff0@54
+|:+0&&|c|a|l@1| |D|r|a|g|i|t|D|o|w|n|L|e|f|t|(|)| @52