Folks,
The segmentation fault occurs when the string to replace is just the
"^" anchor (beginning-of-line) and the point is on an empty line.
Issue occurs on a -current system dated July 11th. (dmesg below).
The following patch prevents the segmentation fault:
--- /usr/src/usr.bin/mg/line.c Mon Jul 13 13:31:14 2020
+++ line.c Mon Jul 13 13:01:49 2020
@@ -556,6 +556,8 @@
goto done;
lp = curwp->w_dotp;
+ if ((lp)->l_text == NULL)
+ goto done;
doto = curwp->w_doto;
n = plen;
However, this reveals another defect. The query-replace-regexp now
never advances beyond the current line and keeps inserting the
replacement text into it. If you've chosen ! (replace rest) mg
eventually runs out of memory.
This is fixed by the second modification to re_search.c shown below. The
first
is required to enable mg to perform the replacement on the current line
when it is empty.
--- /usr/src/usr.bin/mg/re_search.c Mon Jul 13 09:15:11 2020
+++ re_search.c Mon Jul 13 13:34:09 2020
@@ -318,9 +318,9 @@
if (tbo == clp->l_used)
/*
* Don't start matching past end of line -- must move to
- * beginning of next line, unless at end of file.
+ * beginning of next line, unless at end of file or line
empty.
*/
- if (clp != curbp->b_headp) {
+ if (clp != curbp->b_headp && llength(clp) != 0) {
clp = lforw(clp);
tdotline++;
tbo = 0;
@@ -333,7 +333,7 @@
regex_match[0].rm_so = tbo;
regex_match[0].rm_eo = llength(clp);
error = regexec(®ex_buff, ltext(clp) ? ltext(clp) : "",
- RE_NMATCH, regex_match, REG_STARTEND);
+ RE_NMATCH, regex_match,
(tbo==0?0:REG_NOTBOL)|REG_STARTEND);
if (error != 0) {
clp = lforw(clp);
tdotline++;
OpenBSD 6.7-current (GENERIC) #328: Sat Jul 11 20:12:48 MDT 2020
dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC
real mem = 1056899072 (1007MB)
avail mem = 1009971200 (963MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.3 @ 0xf93d0 (338 entries)
bios0: vendor American Megatrends Inc. version "090008" date 12/07/2018
bios0: Microsoft Corporation Virtual Machine
acpi0 at bios0: ACPI 2.0
acpi0: sleep states S0 S5
acpi0: tables DSDT FACP WAET SLIC OEM0 SRAT APIC OEMB
acpi0: wakeup devices
acpitimer0 at acpi0: 3579545 Hz, 32 bits
acpihve0 at acpi0
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
ioapic0 at mainbus0: apid 0 pa 0xfec00000, version 11, 24 pins, remapped
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: AMD Ryzen 7 1700 Eight-Core Processor, 2619.63 MHz, 17-01-01
cpu0:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLU
SH,MMX,FXSR,SSE,SSE2,SSE3,PCLMUL,SSSE3,FMA3,CX16,SSE4.1,SSE4.2,MOVBE,POPCNT,
AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,MMXX,FFXSR,PAGE1GB,RDTSCP,LONG,LAHF,CMPLEG,
AMCR8,ABM,SSE4A,MASSE,3DNOWP,OSVW,FSGSBASE,BMI1,AVX2,SMEP,BMI2,RDSEED,ADX,SM
AP,CLFLUSHOPT,SHA,IBPB,VIRTSSBD,XSAVEOPT,XSAVEC,XGETBV1,XSAVES
cpu0: 64KB 64b/line 4-way I-cache, 32KB 64b/line 8-way D-cache, 512KB
64b/line 8-way L2 cache, 16MB 64b/line 16-way L3 cache
cpu0: ITLB 64 4KB entries fully associative, 64 4MB entries fully
associative
cpu0: DTLB 64 4KB entries fully associative, 64 4MB entries fully
associative
cpu0: smt 0, core 0, package 0
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 169MHz
acpiprt0 at acpi0: bus 0 (PCI0)
acpicpu0 at acpi0: C1(@1 halt!)
acpipci0 at acpi0 PCI0
extent `acpipci0 pcibus' (0x0 - 0xff), flags=0
extent `pciio' (0x0 - 0xffffffff), flags=0
0x10000 - 0xffffffff
extent `pcimem' (0x0 - 0xffffffffffffffff), flags=0
0x0 - 0x3fffffff
0x40000000000 - 0xffffffffffffffff
acpicmos0 at acpi0
"VMBus" at acpi0 not configured
"Hyper_V_Gen_Counter_V1" at acpi0 not configured
pvbus0 at mainbus0: Hyper-V 10.0
hyperv0 at pvbus0: protocol 4.0, features 0x2e7f
hyperv0: heartbeat, kvp, shutdown, timesync
hvs0 at hyperv0 channel 2: ide, protocol 6.2
scsibus1 at hvs0: 2 targets
sd0 at scsibus1 targ 0 lun 0: <Msft, Virtual Disk, 1.0>
naa.60022480e357104f5b7149127201f778
sd0: 25600MB, 512 bytes/sector, 52428800 sectors, thin
hvn0 at hyperv0 channel 14: NVS 5.0 NDIS 6.30, address 00:15:5d:00:10:06
hvs1 at hyperv0 channel 15: scsi, protocol 6.2
scsibus2 at hvs1: 2 targets
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "Intel 82443BX" rev 0x03
pcib0 at pci0 dev 7 function 0 "Intel 82371AB PIIX4 ISA" rev 0x01
pciide0 at pci0 dev 7 function 1 "Intel 82371AB IDE" rev 0x01: DMA, channel
0 wired to compatibility, channel 1 wired to compatibility
pciide0: channel 0 disabled (no drives)
atapiscsi0 at pciide0 channel 1 drive 0
scsibus3 at atapiscsi0: 2 targets
cd0 at scsibus3 targ 0 lun 0: <Msft, Virtual CD/ROM, 1.0> removable
cd0(pciide0:1:0): using PIO mode 4, DMA mode 2
piixpm0 at pci0 dev 7 function 3 "Intel 82371AB Power" rev 0x02: SMBus
disabled
vga1 at pci0 dev 8 function 0 "Microsoft VGA" rev 0x00
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
isa0 at pcib0
isadma0 at isa0
fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
com0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
com1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo
pckbc0 at isa0 port 0x60/5 irq 1 irq 12
pckbd0 at pckbc0 (kbd slot)
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pms0 at pckbc0 (aux slot)
wsmouse0 at pms0 mux 0
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
vscsi0 at root
scsibus4 at vscsi0: 256 targets
softraid0 at root
scsibus5 at softraid0: 256 targets
root on sd0a (7f9b785a6981db5a.a) swap on sd0b dump on sd0b
fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec
fd1 at fdc0 drive 1: density unknown
acpi0: PM1 stuck (en 0x101 st 0x1), clearing
Thanks,
-mark
--
Mark Willson
mark.will...@hydrus.org.uk
https://hydrus.org.uk
