If Make.deps is not writable (e.g. in Perforce client and not opened for...

If Make.deps is not writable (e.g. in Perforce client and not opened for editing), bail out immediately.

R=rsc,r
APPROVED=r
DELTA=7  (5 added, 1 deleted, 1 changed)
OCL=29319
CL=29319

src/lib/Makefile

@@ -5,7 +5,7 @@
 # After editing the DIRS= list or adding imports to any Go files
 # in any of those directories, run:
 #
-#	p4 edit Make.deps; ./deps.bash
+#	./deps.bash
 #
 # to rebuild the dependency information in Make.deps.
 

src/lib/deps.bash

@@ -6,6 +6,11 @@
 OUT="Make.deps"
 TMP="Make.deps.tmp"
 
+if [ -f $OUT ] && ! [ -w $OUT ]; then
+	echo "$0: $OUT is read-only; aborting." 1>&2
+	exit 1
+fi
+
 # Get list of directories from Makefile
 dirs=$(sed '1,/^DIRS=/d; /^$/,$d; s/\\//g' Makefile)
 dirpat=$(echo $dirs | sed 's/ /|/g; s/.*/^(&)$/')
@@ -28,5 +33,4 @@ for dir in $dirs; do (
 	echo $dir.install: $deps
 ) done > $TMP
 
-p4 open $OUT
 mv $TMP $OUT