log -L: fix overlapping input ranges

The existing code was too defensive, and would trigger the assert in
range_set_append() if the user gave overlapping ranges.

The intent was always to define overlapping ranges as just the union
of all of them, as evidenced by the call to sort_and_merge_range_set().
(Which was already used, unlike what the comment said.)

Fix by splitting out the meat of range_set_append() to a new _unsafe()
function that lacks the paranoia.  sort_and_merge_range_set will fix
up the ranges, so we don't need the checks there.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 356 insertions, 0 deletions

diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index 426a82868..2341351e1 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -39,6 +39,12 @@ canned_test "-L 24,+1:a.c simple" vanishes-early
 
 canned_test "-L '/long f/,/^}/:b.c' move-support" move-support-f
 
+canned_test "-L 4,12:a.c -L :main:a.c simple" multiple
+canned_test "-L 4,18:a.c -L :main:a.c simple" multiple-overlapping
+canned_test "-L :main:a.c -L 4,18:a.c simple" multiple-overlapping
+canned_test "-L 4:a.c -L 8,12:a.c simple" multiple-superset
+canned_test "-L 8,12:a.c -L 4:a.c simple" multiple-superset
+
 test_bad_opts "-L" "switch.*requires a value"
 test_bad_opts "-L b.c" "argument.*not of the form"
 test_bad_opts "-L 1:" "argument.*not of the form"
diff --git a/t/t4211/expect.multiple b/t/t4211/expect.multiple
new file mode 100644
index 000000000..76ad5b598
--- /dev/null
+++ b/t/t4211/expect.multiple
@@ -0,0 +1,104 @@
+commit 4659538844daa2849b1a9e7d6fadb96fcd26fc83
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:48:43 2013 +0100
+
+    change back to complete line
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -18,5 +18,7 @@
+ int main ()
+ {
+ 	printf("%ld\n", f(15));
+ 	return 0;
+-}
+\ No newline at end of file
++}
++
++/* incomplete lines are bad! */
+
+commit 100b61a6f2f720f812620a9d10afb3a960ccb73c
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:48:10 2013 +0100
+
+    change to an incomplete line at end
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -18,5 +18,5 @@
+ int main ()
+ {
+ 	printf("%ld\n", f(15));
+ 	return 0;
+-}
++}
+\ No newline at end of file
+
+commit a6eb82647d5d67f893da442f8f9375fd89a3b1e2
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:45:16 2013 +0100
+
+    touch both functions
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,9 +3,9 @@
+-int f(int x)
++long f(long x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
+ 	return s;
+ }
+@@ -17,5 +17,5 @@
+ int main ()
+ {
+-	printf("%d\n", f(15));
++	printf("%ld\n", f(15));
+ 	return 0;
+ }
+
+commit f04fb20f2c77850996cba739709acc6faecc58f7
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:44:55 2013 +0100
+
+    change f()
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,8 +3,9 @@
+ int f(int x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
++	return s;
+ }
+
+commit de4c48ae814792c02a49c4c3c0c757ae69c55f6a
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:44:48 2013 +0100
+
+    initial
+
+diff --git a/a.c b/a.c
+--- /dev/null
++++ b/a.c
+@@ -0,0 +3,8 @@
++int f(int x)
++{
++	int s = 0;
++	while (x) {
++		x >>= 1;
++		s++;
++	}
++}
diff --git a/t/t4211/expect.multiple-overlapping b/t/t4211/expect.multiple-overlapping
new file mode 100644
index 000000000..d930b6eec
--- /dev/null
+++ b/t/t4211/expect.multiple-overlapping
@@ -0,0 +1,187 @@
+commit 4659538844daa2849b1a9e7d6fadb96fcd26fc83
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:48:43 2013 +0100
+
+    change back to complete line
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -4,19 +4,21 @@
+ long f(long x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
+ 	return s;
+ }
+ 
+ /*
+  * This is only an example!
+  */
+ 
+ int main ()
+ {
+ 	printf("%ld\n", f(15));
+ 	return 0;
+-}
+\ No newline at end of file
++}
++
++/* incomplete lines are bad! */
+
+commit 100b61a6f2f720f812620a9d10afb3a960ccb73c
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:48:10 2013 +0100
+
+    change to an incomplete line at end
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -4,19 +4,19 @@
+ long f(long x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
+ 	return s;
+ }
+ 
+ /*
+  * This is only an example!
+  */
+ 
+ int main ()
+ {
+ 	printf("%ld\n", f(15));
+ 	return 0;
+-}
++}
+\ No newline at end of file
+
+commit 39b6eb2d5b706d3322184a169f666f25ed3fbd00
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:45:41 2013 +0100
+
+    touch comment
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,19 +3,19 @@
+ long f(long x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
+ 	return s;
+ }
+ 
+ /*
+- * A comment.
++ * This is only an example!
+  */
+ 
+ int main ()
+ {
+ 	printf("%ld\n", f(15));
+ 	return 0;
+ }
+
+commit a6eb82647d5d67f893da442f8f9375fd89a3b1e2
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:45:16 2013 +0100
+
+    touch both functions
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,19 +3,19 @@
+-int f(int x)
++long f(long x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
+ 	return s;
+ }
+ 
+ /*
+  * A comment.
+  */
+ 
+ int main ()
+ {
+-	printf("%d\n", f(15));
++	printf("%ld\n", f(15));
+ 	return 0;
+ }
+
+commit f04fb20f2c77850996cba739709acc6faecc58f7
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:44:55 2013 +0100
+
+    change f()
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,18 +3,19 @@
+ int f(int x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
++	return s;
+ }
+ 
+ /*
+  * A comment.
+  */
+ 
+ int main ()
+ {
+ 	printf("%d\n", f(15));
+ 	return 0;
+ }
+
+commit de4c48ae814792c02a49c4c3c0c757ae69c55f6a
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:44:48 2013 +0100
+
+    initial
+
+diff --git a/a.c b/a.c
+--- /dev/null
++++ b/a.c
+@@ -0,0 +3,18 @@
++int f(int x)
++{
++	int s = 0;
++	while (x) {
++		x >>= 1;
++		s++;
++	}
++}
++
++/*
++ * A comment.
++ */
++
++int main ()
++{
++	printf("%d\n", f(15));
++	return 0;
++}
diff --git a/t/t4211/expect.multiple-superset b/t/t4211/expect.multiple-superset
new file mode 100644
index 000000000..a1f5bc49c
--- /dev/null
+++ b/t/t4211/expect.multiple-superset
@@ -0,0 +1,59 @@
+commit a6eb82647d5d67f893da442f8f9375fd89a3b1e2
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:45:16 2013 +0100
+
+    touch both functions
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,9 +3,9 @@
+-int f(int x)
++long f(long x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
+ 	return s;
+ }
+
+commit f04fb20f2c77850996cba739709acc6faecc58f7
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:44:55 2013 +0100
+
+    change f()
+
+diff --git a/a.c b/a.c
+--- a/a.c
++++ b/a.c
+@@ -3,8 +3,9 @@
+ int f(int x)
+ {
+ 	int s = 0;
+ 	while (x) {
+ 		x >>= 1;
+ 		s++;
+ 	}
++	return s;
+ }
+
+commit de4c48ae814792c02a49c4c3c0c757ae69c55f6a
+Author: Thomas Rast <trast@student.ethz.ch>
+Date:   Thu Feb 28 10:44:48 2013 +0100
+
+    initial
+
+diff --git a/a.c b/a.c
+--- /dev/null
++++ b/a.c
+@@ -0,0 +3,8 @@
++int f(int x)
++{
++	int s = 0;
++	while (x) {
++		x >>= 1;
++		s++;
++	}
++}