From 37dac22ccc806f748a5e5509c8ef78696af7c104 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 09:34:04 -0700
Subject: [PATCH 01/20] stub for new res1 test

---
 src/apps/testapps/testCompactCells.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 94e1d01e8..cf4269263 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -91,6 +91,14 @@ SUITE(compactCells) {
         free(children);
     }
 
+    TEST(allRes0children) {
+        H3Index cells0[122];
+
+        H3_EXPORT(getRes0Cells)(&cells0);
+
+        t_assert(cells0[0] == 0x8001fffffffffff, "got expected parent");
+    }
+
     TEST(res0) {
         int hexCount = NUM_BASE_CELLS;
 

From a094639eecbe6940bea29c7d0425f46918a7d110 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 09:34:23 -0700
Subject: [PATCH 02/20] better name

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index cf4269263..79125f07f 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -91,7 +91,7 @@ SUITE(compactCells) {
         free(children);
     }
 
-    TEST(allRes0children) {
+    TEST(allRes1) {
         H3Index cells0[122];
 
         H3_EXPORT(getRes0Cells)(&cells0);

From a618a5ee9f3ade61c1e0bc2e44550306bb6c91e2 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 09:35:32 -0700
Subject: [PATCH 03/20] formatting is happening?

---
 src/apps/applib/include/args.h               |  4 +--
 src/apps/benchmarks/benchmarkGridPathCells.c | 10 +++-----
 src/apps/benchmarks/benchmarkH3Api.c         |  5 ++--
 src/apps/benchmarks/benchmarkVertex.c        |  5 ++--
 src/h3lib/include/h3Index.h                  | 27 +++++++++++---------
 5 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/src/apps/applib/include/args.h b/src/apps/applib/include/args.h
index 511913836..038038b03 100644
--- a/src/apps/applib/include/args.h
+++ b/src/apps/applib/include/args.h
@@ -90,7 +90,7 @@ int _parseArgsList(int argc, char *argv[], int numArgs, Arg *args[],
 // common arguments
 
 #define ARG_HELP \
-    { .names = {"-h", "--help"}, .helpText = "Show this help message." }
+    {.names = {"-h", "--help"}, .helpText = "Show this help message."}
 #define DEFINE_INDEX_ARG(varName, argName) \
     H3Index varName = 0;                   \
     Arg argName = {                        \
@@ -109,7 +109,7 @@ int _parseArgsList(int argc, char *argv[], int numArgs, Arg *args[],
                    .value = &varName,         \
                    .helpText = "H3 Cell"}
 #define ARG_KML \
-    { .names = {"-k", "--kml"}, .helpText = "Print output in KML format." }
+    {.names = {"-k", "--kml"}, .helpText = "Print output in KML format."}
 #define DEFINE_KML_NAME_ARG(varName, argName)      \
     char varName[BUFF_SIZE] = {0};                 \
     Arg argName = {                                \
diff --git a/src/apps/benchmarks/benchmarkGridPathCells.c b/src/apps/benchmarks/benchmarkGridPathCells.c
index 2fcbaeb92..333fe967e 100644
--- a/src/apps/benchmarks/benchmarkGridPathCells.c
+++ b/src/apps/benchmarks/benchmarkGridPathCells.c
@@ -27,12 +27,10 @@ int64_t size;
 H3_EXPORT(gridPathCellsSize)(startIndex, endFar, &size);
 H3Index *out = calloc(size, sizeof(H3Index));
 
-BENCHMARK(gridPathCellsNear, 10000, {
-    H3_EXPORT(gridPathCells)(startIndex, endNear, out);
-});
-BENCHMARK(gridPathCellsFar, 1000, {
-    H3_EXPORT(gridPathCells)(startIndex, endFar, out);
-});
+BENCHMARK(gridPathCellsNear, 10000,
+          { H3_EXPORT(gridPathCells)(startIndex, endNear, out); });
+BENCHMARK(gridPathCellsFar, 1000,
+          { H3_EXPORT(gridPathCells)(startIndex, endFar, out); });
 
 free(out);
 
diff --git a/src/apps/benchmarks/benchmarkH3Api.c b/src/apps/benchmarks/benchmarkH3Api.c
index d54b66597..22ec3ca8f 100644
--- a/src/apps/benchmarks/benchmarkH3Api.c
+++ b/src/apps/benchmarks/benchmarkH3Api.c
@@ -31,8 +31,7 @@ BENCHMARK(latLngToCell, 10000, { H3_EXPORT(latLngToCell)(&coord, 9, &h); });
 
 BENCHMARK(cellToLatLng, 10000, { H3_EXPORT(cellToLatLng)(hex, &outCoord); });
 
-BENCHMARK(cellToBoundary, 10000, {
-    H3_EXPORT(cellToBoundary)(hex, &outBoundary);
-});
+BENCHMARK(cellToBoundary, 10000,
+          { H3_EXPORT(cellToBoundary)(hex, &outBoundary); });
 
 END_BENCHMARKS();
diff --git a/src/apps/benchmarks/benchmarkVertex.c b/src/apps/benchmarks/benchmarkVertex.c
index a0bd6c01d..38e90cff0 100644
--- a/src/apps/benchmarks/benchmarkVertex.c
+++ b/src/apps/benchmarks/benchmarkVertex.c
@@ -44,9 +44,8 @@ H3Index *vertexes = calloc(6, sizeof(H3Index));
 
 BENCHMARK(cellToVertexes, 10000, { H3_EXPORT(cellToVertexes)(hex, vertexes); });
 
-BENCHMARK(cellToVertexesPent, 10000, {
-    H3_EXPORT(cellToVertexes)(pentagon, vertexes);
-});
+BENCHMARK(cellToVertexesPent, 10000,
+          { H3_EXPORT(cellToVertexes)(pentagon, vertexes); });
 
 BENCHMARK(cellToVertexesRing, 10000, {
     for (int i = 0; i < ring2Count; i++) {
diff --git a/src/h3lib/include/h3Index.h b/src/h3lib/include/h3Index.h
index 6ced3c4cd..5dfa7ce3d 100644
--- a/src/h3lib/include/h3Index.h
+++ b/src/h3lib/include/h3Index.h
@@ -92,47 +92,50 @@
 /**
  * Gets the highest bit of the H3 index.
  */
-#define H3_GET_HIGH_BIT(h3) ((int)((((h3)&H3_HIGH_BIT_MASK) >> H3_MAX_OFFSET)))
+#define H3_GET_HIGH_BIT(h3) \
+    ((int)((((h3) & H3_HIGH_BIT_MASK) >> H3_MAX_OFFSET)))
 
 /**
  * Sets the highest bit of the h3 to v.
  */
-#define H3_SET_HIGH_BIT(h3, v)                 \
-    (h3) = (((h3)&H3_HIGH_BIT_MASK_NEGATIVE) | \
+#define H3_SET_HIGH_BIT(h3, v)                   \
+    (h3) = (((h3) & H3_HIGH_BIT_MASK_NEGATIVE) | \
             (((uint64_t)(v)) << H3_MAX_OFFSET))
 
 /**
  * Gets the integer mode of h3.
  */
-#define H3_GET_MODE(h3) ((int)((((h3)&H3_MODE_MASK) >> H3_MODE_OFFSET)))
+#define H3_GET_MODE(h3) ((int)((((h3) & H3_MODE_MASK) >> H3_MODE_OFFSET)))
 
 /**
  * Sets the integer mode of h3 to v.
  */
 #define H3_SET_MODE(h3, v) \
-    (h3) = (((h3)&H3_MODE_MASK_NEGATIVE) | (((uint64_t)(v)) << H3_MODE_OFFSET))
+    (h3) =                 \
+        (((h3) & H3_MODE_MASK_NEGATIVE) | (((uint64_t)(v)) << H3_MODE_OFFSET))
 
 /**
  * Gets the integer base cell of h3.
  */
-#define H3_GET_BASE_CELL(h3) ((int)((((h3)&H3_BC_MASK) >> H3_BC_OFFSET)))
+#define H3_GET_BASE_CELL(h3) ((int)((((h3) & H3_BC_MASK) >> H3_BC_OFFSET)))
 
 /**
  * Sets the integer base cell of h3 to bc.
  */
 #define H3_SET_BASE_CELL(h3, bc) \
-    (h3) = (((h3)&H3_BC_MASK_NEGATIVE) | (((uint64_t)(bc)) << H3_BC_OFFSET))
+    (h3) = (((h3) & H3_BC_MASK_NEGATIVE) | (((uint64_t)(bc)) << H3_BC_OFFSET))
 
 /**
  * Gets the integer resolution of h3.
  */
-#define H3_GET_RESOLUTION(h3) ((int)((((h3)&H3_RES_MASK) >> H3_RES_OFFSET)))
+#define H3_GET_RESOLUTION(h3) ((int)((((h3) & H3_RES_MASK) >> H3_RES_OFFSET)))
 
 /**
  * Sets the integer resolution of h3.
  */
 #define H3_SET_RESOLUTION(h3, res) \
-    (h3) = (((h3)&H3_RES_MASK_NEGATIVE) | (((uint64_t)(res)) << H3_RES_OFFSET))
+    (h3) =                         \
+        (((h3) & H3_RES_MASK_NEGATIVE) | (((uint64_t)(res)) << H3_RES_OFFSET))
 
 /**
  * Gets the resolution res integer digit (0-7) of h3.
@@ -145,15 +148,15 @@
  * Sets a value in the reserved space. Setting to non-zero may produce invalid
  * indexes.
  */
-#define H3_SET_RESERVED_BITS(h3, v)            \
-    (h3) = (((h3)&H3_RESERVED_MASK_NEGATIVE) | \
+#define H3_SET_RESERVED_BITS(h3, v)              \
+    (h3) = (((h3) & H3_RESERVED_MASK_NEGATIVE) | \
             (((uint64_t)(v)) << H3_RESERVED_OFFSET))
 
 /**
  * Gets a value in the reserved space. Should always be zero for valid indexes.
  */
 #define H3_GET_RESERVED_BITS(h3) \
-    ((int)((((h3)&H3_RESERVED_MASK) >> H3_RESERVED_OFFSET)))
+    ((int)((((h3) & H3_RESERVED_MASK) >> H3_RESERVED_OFFSET)))
 
 /**
  * Sets the resolution res digit of h3 to the integer digit (0-7)

From 63a27237d61fd8408dab1f0a582397b620f5c8e1 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 10:01:42 -0700
Subject: [PATCH 04/20] clean up test for all res 1

---
 src/apps/testapps/testCompactCells.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 79125f07f..9dff87729 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -92,11 +92,20 @@ SUITE(compactCells) {
     }
 
     TEST(allRes1) {
-        H3Index cells0[122];
+        int64_t numRes0 = 122;
+        int64_t numRes1 = 842;
+        H3Index cells0[numRes0];
+        H3Index cells1[numRes1];
 
         H3_EXPORT(getRes0Cells)(&cells0);
+        t_assert(cells0[0] == 0x8001fffffffffff, "got expected first res0 cell");
 
-        t_assert(cells0[0] == 0x8001fffffffffff, "got expected parent");
+        t_assertSuccess(
+            H3_EXPORT(uncompactCells)(cells0, numRes0, cells1, numRes1, 1));
+
+        H3Index out[numRes1];
+        // also dies at 41!
+        t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numRes1));
     }
 
     TEST(res0) {

From e5fa3bb182106236163fcbff7caed52931e39c36 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 10:20:44 -0700
Subject: [PATCH 05/20] failing test

---
 src/apps/testapps/testCompactCells.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 9dff87729..363e93926 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -98,14 +98,22 @@ SUITE(compactCells) {
         H3Index cells1[numRes1];
 
         H3_EXPORT(getRes0Cells)(&cells0);
-        t_assert(cells0[0] == 0x8001fffffffffff, "got expected first res0 cell");
+        t_assert(cells0[0] == 0x8001fffffffffff,
+                 "got expected first res0 cell");
 
         t_assertSuccess(
             H3_EXPORT(uncompactCells)(cells0, numRes0, cells1, numRes1, 1));
 
         H3Index out[numRes1];
-        // also dies at 41!
-        t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numRes1));
+
+        // Fails at compactCells.
+        // However:
+        //   Passes if numUncompacted <= 40
+        //   Fails  if numUncompacted >= 41.
+        int64_t numUncompacted = numRes1;
+        t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
+
+        // TODO: check that output matches cells0
     }
 
     TEST(res0) {

From 8f778296777a0525de3efc19c73b3102c526fa90 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 10:25:38 -0700
Subject: [PATCH 06/20] Demonstrate pass at `numUncompacted = 40`

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 363e93926..9fe3c7eec 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -110,7 +110,7 @@ SUITE(compactCells) {
         // However:
         //   Passes if numUncompacted <= 40
         //   Fails  if numUncompacted >= 41.
-        int64_t numUncompacted = numRes1;
+        int64_t numUncompacted = 40;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
         // TODO: check that output matches cells0

From 944a62b04ef8420173fc56e964d6b501b07ad60d Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 10:33:34 -0700
Subject: [PATCH 07/20] retry: Demonstrate pass at `numUncompacted = 40`

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 9fe3c7eec..2887e4d8b 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -97,7 +97,7 @@ SUITE(compactCells) {
         H3Index cells0[numRes0];
         H3Index cells1[numRes1];
 
-        H3_EXPORT(getRes0Cells)(&cells0);
+        H3_EXPORT(getRes0Cells)(cells0);
         t_assert(cells0[0] == 0x8001fffffffffff,
                  "got expected first res0 cell");
 

From 6159f5ca866a2b9c17c5784e44b44fe8190e3fea Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 10:51:30 -0700
Subject: [PATCH 08/20] should fix the formatting issue

---
 src/apps/applib/include/args.h               |  4 +--
 src/apps/benchmarks/benchmarkGridPathCells.c | 10 +++++---
 src/apps/benchmarks/benchmarkH3Api.c         |  5 ++--
 src/apps/benchmarks/benchmarkVertex.c        |  5 ++--
 src/h3lib/include/h3Index.h                  | 27 +++++++++-----------
 5 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/src/apps/applib/include/args.h b/src/apps/applib/include/args.h
index 038038b03..511913836 100644
--- a/src/apps/applib/include/args.h
+++ b/src/apps/applib/include/args.h
@@ -90,7 +90,7 @@ int _parseArgsList(int argc, char *argv[], int numArgs, Arg *args[],
 // common arguments
 
 #define ARG_HELP \
-    {.names = {"-h", "--help"}, .helpText = "Show this help message."}
+    { .names = {"-h", "--help"}, .helpText = "Show this help message." }
 #define DEFINE_INDEX_ARG(varName, argName) \
     H3Index varName = 0;                   \
     Arg argName = {                        \
@@ -109,7 +109,7 @@ int _parseArgsList(int argc, char *argv[], int numArgs, Arg *args[],
                    .value = &varName,         \
                    .helpText = "H3 Cell"}
 #define ARG_KML \
-    {.names = {"-k", "--kml"}, .helpText = "Print output in KML format."}
+    { .names = {"-k", "--kml"}, .helpText = "Print output in KML format." }
 #define DEFINE_KML_NAME_ARG(varName, argName)      \
     char varName[BUFF_SIZE] = {0};                 \
     Arg argName = {                                \
diff --git a/src/apps/benchmarks/benchmarkGridPathCells.c b/src/apps/benchmarks/benchmarkGridPathCells.c
index 333fe967e..2fcbaeb92 100644
--- a/src/apps/benchmarks/benchmarkGridPathCells.c
+++ b/src/apps/benchmarks/benchmarkGridPathCells.c
@@ -27,10 +27,12 @@ int64_t size;
 H3_EXPORT(gridPathCellsSize)(startIndex, endFar, &size);
 H3Index *out = calloc(size, sizeof(H3Index));
 
-BENCHMARK(gridPathCellsNear, 10000,
-          { H3_EXPORT(gridPathCells)(startIndex, endNear, out); });
-BENCHMARK(gridPathCellsFar, 1000,
-          { H3_EXPORT(gridPathCells)(startIndex, endFar, out); });
+BENCHMARK(gridPathCellsNear, 10000, {
+    H3_EXPORT(gridPathCells)(startIndex, endNear, out);
+});
+BENCHMARK(gridPathCellsFar, 1000, {
+    H3_EXPORT(gridPathCells)(startIndex, endFar, out);
+});
 
 free(out);
 
diff --git a/src/apps/benchmarks/benchmarkH3Api.c b/src/apps/benchmarks/benchmarkH3Api.c
index 22ec3ca8f..d54b66597 100644
--- a/src/apps/benchmarks/benchmarkH3Api.c
+++ b/src/apps/benchmarks/benchmarkH3Api.c
@@ -31,7 +31,8 @@ BENCHMARK(latLngToCell, 10000, { H3_EXPORT(latLngToCell)(&coord, 9, &h); });
 
 BENCHMARK(cellToLatLng, 10000, { H3_EXPORT(cellToLatLng)(hex, &outCoord); });
 
-BENCHMARK(cellToBoundary, 10000,
-          { H3_EXPORT(cellToBoundary)(hex, &outBoundary); });
+BENCHMARK(cellToBoundary, 10000, {
+    H3_EXPORT(cellToBoundary)(hex, &outBoundary);
+});
 
 END_BENCHMARKS();
diff --git a/src/apps/benchmarks/benchmarkVertex.c b/src/apps/benchmarks/benchmarkVertex.c
index 38e90cff0..a0bd6c01d 100644
--- a/src/apps/benchmarks/benchmarkVertex.c
+++ b/src/apps/benchmarks/benchmarkVertex.c
@@ -44,8 +44,9 @@ H3Index *vertexes = calloc(6, sizeof(H3Index));
 
 BENCHMARK(cellToVertexes, 10000, { H3_EXPORT(cellToVertexes)(hex, vertexes); });
 
-BENCHMARK(cellToVertexesPent, 10000,
-          { H3_EXPORT(cellToVertexes)(pentagon, vertexes); });
+BENCHMARK(cellToVertexesPent, 10000, {
+    H3_EXPORT(cellToVertexes)(pentagon, vertexes);
+});
 
 BENCHMARK(cellToVertexesRing, 10000, {
     for (int i = 0; i < ring2Count; i++) {
diff --git a/src/h3lib/include/h3Index.h b/src/h3lib/include/h3Index.h
index 5dfa7ce3d..6ced3c4cd 100644
--- a/src/h3lib/include/h3Index.h
+++ b/src/h3lib/include/h3Index.h
@@ -92,50 +92,47 @@
 /**
  * Gets the highest bit of the H3 index.
  */
-#define H3_GET_HIGH_BIT(h3) \
-    ((int)((((h3) & H3_HIGH_BIT_MASK) >> H3_MAX_OFFSET)))
+#define H3_GET_HIGH_BIT(h3) ((int)((((h3)&H3_HIGH_BIT_MASK) >> H3_MAX_OFFSET)))
 
 /**
  * Sets the highest bit of the h3 to v.
  */
-#define H3_SET_HIGH_BIT(h3, v)                   \
-    (h3) = (((h3) & H3_HIGH_BIT_MASK_NEGATIVE) | \
+#define H3_SET_HIGH_BIT(h3, v)                 \
+    (h3) = (((h3)&H3_HIGH_BIT_MASK_NEGATIVE) | \
             (((uint64_t)(v)) << H3_MAX_OFFSET))
 
 /**
  * Gets the integer mode of h3.
  */
-#define H3_GET_MODE(h3) ((int)((((h3) & H3_MODE_MASK) >> H3_MODE_OFFSET)))
+#define H3_GET_MODE(h3) ((int)((((h3)&H3_MODE_MASK) >> H3_MODE_OFFSET)))
 
 /**
  * Sets the integer mode of h3 to v.
  */
 #define H3_SET_MODE(h3, v) \
-    (h3) =                 \
-        (((h3) & H3_MODE_MASK_NEGATIVE) | (((uint64_t)(v)) << H3_MODE_OFFSET))
+    (h3) = (((h3)&H3_MODE_MASK_NEGATIVE) | (((uint64_t)(v)) << H3_MODE_OFFSET))
 
 /**
  * Gets the integer base cell of h3.
  */
-#define H3_GET_BASE_CELL(h3) ((int)((((h3) & H3_BC_MASK) >> H3_BC_OFFSET)))
+#define H3_GET_BASE_CELL(h3) ((int)((((h3)&H3_BC_MASK) >> H3_BC_OFFSET)))
 
 /**
  * Sets the integer base cell of h3 to bc.
  */
 #define H3_SET_BASE_CELL(h3, bc) \
-    (h3) = (((h3) & H3_BC_MASK_NEGATIVE) | (((uint64_t)(bc)) << H3_BC_OFFSET))
+    (h3) = (((h3)&H3_BC_MASK_NEGATIVE) | (((uint64_t)(bc)) << H3_BC_OFFSET))
 
 /**
  * Gets the integer resolution of h3.
  */
-#define H3_GET_RESOLUTION(h3) ((int)((((h3) & H3_RES_MASK) >> H3_RES_OFFSET)))
+#define H3_GET_RESOLUTION(h3) ((int)((((h3)&H3_RES_MASK) >> H3_RES_OFFSET)))
 
 /**
  * Sets the integer resolution of h3.
  */
 #define H3_SET_RESOLUTION(h3, res) \
-    (h3) =                         \
-        (((h3) & H3_RES_MASK_NEGATIVE) | (((uint64_t)(res)) << H3_RES_OFFSET))
+    (h3) = (((h3)&H3_RES_MASK_NEGATIVE) | (((uint64_t)(res)) << H3_RES_OFFSET))
 
 /**
  * Gets the resolution res integer digit (0-7) of h3.
@@ -148,15 +145,15 @@
  * Sets a value in the reserved space. Setting to non-zero may produce invalid
  * indexes.
  */
-#define H3_SET_RESERVED_BITS(h3, v)              \
-    (h3) = (((h3) & H3_RESERVED_MASK_NEGATIVE) | \
+#define H3_SET_RESERVED_BITS(h3, v)            \
+    (h3) = (((h3)&H3_RESERVED_MASK_NEGATIVE) | \
             (((uint64_t)(v)) << H3_RESERVED_OFFSET))
 
 /**
  * Gets a value in the reserved space. Should always be zero for valid indexes.
  */
 #define H3_GET_RESERVED_BITS(h3) \
-    ((int)((((h3) & H3_RESERVED_MASK) >> H3_RESERVED_OFFSET)))
+    ((int)((((h3)&H3_RESERVED_MASK) >> H3_RESERVED_OFFSET)))
 
 /**
  * Sets the resolution res digit of h3 to the integer digit (0-7)

From d811d474297d25cb86bcd47f7e36bbd9a3807cb0 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 11:14:39 -0700
Subject: [PATCH 09/20] const array sizes to fix windows errors

---
 src/apps/testapps/testCompactCells.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 2887e4d8b..05ea031bb 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -92,8 +92,8 @@ SUITE(compactCells) {
     }
 
     TEST(allRes1) {
-        int64_t numRes0 = 122;
-        int64_t numRes1 = 842;
+        const int64_t numRes0 = 122;
+        const int64_t numRes1 = 842;
         H3Index cells0[numRes0];
         H3Index cells1[numRes1];
 

From d29c9b3daac76862f547517a5f3b3bc04cfac1ed Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 11:33:19 -0700
Subject: [PATCH 10/20] bah

---
 src/apps/testapps/testCompactCells.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 05ea031bb..192fc4fee 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -94,8 +94,9 @@ SUITE(compactCells) {
     TEST(allRes1) {
         const int64_t numRes0 = 122;
         const int64_t numRes1 = 842;
-        H3Index cells0[numRes0];
-        H3Index cells1[numRes1];
+        H3Index *cells0 = calloc(numRes0, sizeof(H3Index));
+        H3Index *cells1 = calloc(numRes1, sizeof(H3Index));
+        H3Index *out = calloc(numRes1, sizeof(H3Index));
 
         H3_EXPORT(getRes0Cells)(cells0);
         t_assert(cells0[0] == 0x8001fffffffffff,
@@ -104,8 +105,6 @@ SUITE(compactCells) {
         t_assertSuccess(
             H3_EXPORT(uncompactCells)(cells0, numRes0, cells1, numRes1, 1));
 
-        H3Index out[numRes1];
-
         // Fails at compactCells.
         // However:
         //   Passes if numUncompacted <= 40
@@ -114,6 +113,10 @@ SUITE(compactCells) {
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
         // TODO: check that output matches cells0
+
+        free(cells0);
+        free(cells1);
+        free(out);
     }
 
     TEST(res0) {

From fa3b1b8040c34255ab67541ea9bae5952b34d2dd Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 11:42:42 -0700
Subject: [PATCH 11/20] Demonstrate failure at numUncompacted = 41

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 192fc4fee..b7b45f7fb 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -109,7 +109,7 @@ SUITE(compactCells) {
         // However:
         //   Passes if numUncompacted <= 40
         //   Fails  if numUncompacted >= 41.
-        int64_t numUncompacted = 40;
+        int64_t numUncompacted = 41;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
         // TODO: check that output matches cells0

From e6c47e019068823c289c2597d8ec73856b5b2cc4 Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 11:43:30 -0700
Subject: [PATCH 12/20] Demonstrate failure at numUncompacted = numRes1 = 842;

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index b7b45f7fb..b1ff58fea 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -109,7 +109,7 @@ SUITE(compactCells) {
         // However:
         //   Passes if numUncompacted <= 40
         //   Fails  if numUncompacted >= 41.
-        int64_t numUncompacted = 41;
+        int64_t numUncompacted = numRes1;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
         // TODO: check that output matches cells0

From a3a28e61804d6082a10adfa966d40e7301c2761e Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 11:44:11 -0700
Subject: [PATCH 13/20] Demonstrate pass at numUncompacted = 40

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index b1ff58fea..192fc4fee 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -109,7 +109,7 @@ SUITE(compactCells) {
         // However:
         //   Passes if numUncompacted <= 40
         //   Fails  if numUncompacted >= 41.
-        int64_t numUncompacted = numRes1;
+        int64_t numUncompacted = 40;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
         // TODO: check that output matches cells0

From d97b939189a412fed8ea8f5d271e38cbcfb9a67c Mon Sep 17 00:00:00 2001
From: AJ Friend <ajfriend@gmail.com>
Date: Thu, 26 Sep 2024 12:36:05 -0700
Subject: [PATCH 14/20] back to the full failing test demonstrating the problem

---
 src/apps/testapps/testCompactCells.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 192fc4fee..b1ff58fea 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -109,7 +109,7 @@ SUITE(compactCells) {
         // However:
         //   Passes if numUncompacted <= 40
         //   Fails  if numUncompacted >= 41.
-        int64_t numUncompacted = 40;
+        int64_t numUncompacted = numRes1;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
         // TODO: check that output matches cells0

From f199548e326d7b73626fee6a275364d066d3554b Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Sun, 29 Sep 2024 10:32:52 -0700
Subject: [PATCH 15/20] proposed fix for compact

---
 src/apps/testapps/testCompactCells.c |  4 +-
 src/h3lib/lib/h3Index.c              | 68 +++++++++++++++-------------
 2 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index b1ff58fea..2a56c7ae5 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -386,9 +386,7 @@ SUITE(compactCells) {
                          0x7,
                          0x400000000};
         H3Index output[43] = {0};
-        t_assert(H3_EXPORT(compactCells)(bad, output, numHex) == E_RES_DOMAIN,
-                 "compactCells returns E_RES_DOMAIN on bad input (parent "
-                 "error #2)");
+        t_assertSuccess(H3_EXPORT(compactCells)(bad, output, numHex));
     }
 
     TEST(uncompactCells_wrongRes) {
diff --git a/src/h3lib/lib/h3Index.c b/src/h3lib/lib/h3Index.c
index 193622caf..456a4c8f3 100644
--- a/src/h3lib/lib/h3Index.c
+++ b/src/h3lib/lib/h3Index.c
@@ -480,43 +480,49 @@ H3Error H3_EXPORT(compactCells)(const H3Index *h3Set, H3Index *compactedSet,
             H3Index currIndex = remainingHexes[i];
             // TODO: This case is coverable (reachable by fuzzer)
             if (currIndex != H3_NULL) {
-                H3Index parent;
-                H3Error parentError =
-                    H3_EXPORT(cellToParent)(currIndex, parentRes, &parent);
-                if (parentError) {
-                    H3_MEMORY(free)(compactableHexes);
-                    H3_MEMORY(free)(remainingHexes);
-                    H3_MEMORY(free)(hashSetArray);
-                    return parentError;
-                }
-                // Modulus hash the parent into the temp array
-                // to determine if this index was included in
-                // the compactableHexes array
-                int loc = (int)(parent % numRemainingHexes);
-                int loopCount = 0;
                 bool isUncompactable = true;
-                do {
-                    if (NEVER(loopCount > numRemainingHexes)) {
-                        // This case should not be possible because at most one
-                        // index is placed into hashSetArray per input hexagon.
+                // Resolution 0 cells always uncompactable, and trying to take
+                // the res -1 parent of a cell is invalid.
+                if (parentRes >= 0) {
+                    H3Index parent;
+                    H3Error parentError =
+                        H3_EXPORT(cellToParent)(currIndex, parentRes, &parent);
+                    if (parentError) {
                         H3_MEMORY(free)(compactableHexes);
                         H3_MEMORY(free)(remainingHexes);
                         H3_MEMORY(free)(hashSetArray);
-                        return E_FAILED;
+                        return parentError;
                     }
-                    H3Index tempIndex =
-                        hashSetArray[loc] & H3_RESERVED_MASK_NEGATIVE;
-                    if (tempIndex == parent) {
-                        int count = H3_GET_RESERVED_BITS(hashSetArray[loc]) + 1;
-                        if (count == 7) {
-                            isUncompactable = false;
+                    // Modulus hash the parent into the temp array
+                    // to determine if this index was included in
+                    // the compactableHexes array
+                    int loc = (int)(parent % numRemainingHexes);
+                    int loopCount = 0;
+                    do {
+                        if (NEVER(loopCount > numRemainingHexes)) {
+                            // This case should not be possible because at most
+                            // one index is placed into hashSetArray per input
+                            // hexagon.
+                            H3_MEMORY(free)(compactableHexes);
+                            H3_MEMORY(free)(remainingHexes);
+                            H3_MEMORY(free)(hashSetArray);
+                            return E_FAILED;
                         }
-                        break;
-                    } else {
-                        loc = (loc + 1) % numRemainingHexes;
-                    }
-                    loopCount++;
-                } while (hashSetArray[loc] != parent);
+                        H3Index tempIndex =
+                            hashSetArray[loc] & H3_RESERVED_MASK_NEGATIVE;
+                        if (tempIndex == parent) {
+                            int count =
+                                H3_GET_RESERVED_BITS(hashSetArray[loc]) + 1;
+                            if (count == 7) {
+                                isUncompactable = false;
+                            }
+                            break;
+                        } else {
+                            loc = (loc + 1) % numRemainingHexes;
+                        }
+                        loopCount++;
+                    } while (hashSetArray[loc] != parent);
+                }
                 if (isUncompactable) {
                     compactedSetOffset[uncompactableCount] = remainingHexes[i];
                     uncompactableCount++;

From 663e02a305e8adf211ef4f0a312e43235e5570c0 Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Sun, 29 Sep 2024 10:35:25 -0700
Subject: [PATCH 16/20] test other case

---
 src/apps/testapps/testCompactCells.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 2a56c7ae5..c07507be7 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -15,6 +15,7 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 
 #include "constants.h"
 #include "h3Index.h"
@@ -112,6 +113,18 @@ SUITE(compactCells) {
         int64_t numUncompacted = numRes1;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
+        memset(out, 0, sizeof(H3Index) * numRes1);
+
+        numUncompacted = 44;
+        t_assertSuccess(
+            H3_EXPORT(compactCells)(&cells1[80], out, numUncompacted));
+
+        memset(out, 0, sizeof(H3Index) * numRes1);
+
+        numUncompacted = 43;
+        t_assertSuccess(
+            H3_EXPORT(compactCells)(&cells1[80], out, numUncompacted));
+
         // TODO: check that output matches cells0
 
         free(cells0);

From a7e07fe53f2a41c0c24a849e1c4d1b69691bda55 Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Sun, 29 Sep 2024 10:40:33 -0700
Subject: [PATCH 17/20] comprehensive test

---
 src/apps/testapps/testCompactCells.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index c07507be7..56ae5baee 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -113,19 +113,17 @@ SUITE(compactCells) {
         int64_t numUncompacted = numRes1;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
-        memset(out, 0, sizeof(H3Index) * numRes1);
-
-        numUncompacted = 44;
-        t_assertSuccess(
-            H3_EXPORT(compactCells)(&cells1[80], out, numUncompacted));
-
-        memset(out, 0, sizeof(H3Index) * numRes1);
+        // TODO: check that output matches cells0
 
-        numUncompacted = 43;
-        t_assertSuccess(
-            H3_EXPORT(compactCells)(&cells1[80], out, numUncompacted));
+        for (int64_t offset = 0; offset < numRes1; offset++) {
+            for (numUncompacted = numRes1 - offset; numUncompacted >= 0;
+                 numUncompacted--) {
+                memset(out, 0, sizeof(H3Index) * numRes1);
 
-        // TODO: check that output matches cells0
+                t_assertSuccess(H3_EXPORT(compactCells)(&cells1[offset], out,
+                                                        numUncompacted));
+            }
+        }
 
         free(cells0);
         free(cells1);

From 6eb6ca84395e60e6882382e8ca1dd9c20ce85299 Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Sun, 29 Sep 2024 10:46:41 -0700
Subject: [PATCH 18/20] NEVER for parent error

---
 src/h3lib/lib/h3Index.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/h3lib/lib/h3Index.c b/src/h3lib/lib/h3Index.c
index 456a4c8f3..489421e85 100644
--- a/src/h3lib/lib/h3Index.c
+++ b/src/h3lib/lib/h3Index.c
@@ -487,7 +487,7 @@ H3Error H3_EXPORT(compactCells)(const H3Index *h3Set, H3Index *compactedSet,
                     H3Index parent;
                     H3Error parentError =
                         H3_EXPORT(cellToParent)(currIndex, parentRes, &parent);
-                    if (parentError) {
+                    if (NEVER(parentError)) {
                         H3_MEMORY(free)(compactableHexes);
                         H3_MEMORY(free)(remainingHexes);
                         H3_MEMORY(free)(hashSetArray);

From bd81be6ba62ba8ac1c7a2f4f20a6c237c59377f0 Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Mon, 30 Sep 2024 16:53:20 -0600
Subject: [PATCH 19/20] assert that all res 0 cells are found

---
 src/apps/testapps/testCompactCells.c | 53 ++++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 6 deletions(-)

diff --git a/src/apps/testapps/testCompactCells.c b/src/apps/testapps/testCompactCells.c
index 56ae5baee..bab73abc2 100644
--- a/src/apps/testapps/testCompactCells.c
+++ b/src/apps/testapps/testCompactCells.c
@@ -106,17 +106,58 @@ SUITE(compactCells) {
         t_assertSuccess(
             H3_EXPORT(uncompactCells)(cells0, numRes0, cells1, numRes1, 1));
 
-        // Fails at compactCells.
-        // However:
-        //   Passes if numUncompacted <= 40
-        //   Fails  if numUncompacted >= 41.
         int64_t numUncompacted = numRes1;
         t_assertSuccess(H3_EXPORT(compactCells)(cells1, out, numUncompacted));
 
-        // TODO: check that output matches cells0
+        // Assert that the output of this function matches exactly the set of
+        // res 0 cells
+        size_t foundCount = 0;
+        for (size_t res1Idx = 0; res1Idx < numRes1; res1Idx++) {
+            H3Index compactedCell = out[res1Idx];
+
+            if (compactedCell) {
+                for (size_t res1DupIdx = 0; res1DupIdx < res1Idx;
+                     res1DupIdx++) {
+                    t_assert(out[res1DupIdx] != compactedCell,
+                             "Duplicated output found");
+                }
+
+                bool found = false;
+                for (size_t res0Idx = 0; res0Idx < numRes0; res0Idx++) {
+                    if (cells0[res0Idx] == compactedCell) {
+                        found = true;
+                        break;
+                    }
+                }
+                t_assert(found, "Res 0 cell is found");
+                foundCount++;
+            }
+        }
+        t_assert(foundCount == numRes0, "all res 0 cells found");
+
+        free(cells0);
+        free(cells1);
+        free(out);
+    }
+
+    TEST(allRes1_variousRanges) {
+        const int64_t numRes0 = 122;
+        const int64_t numRes1 = 842;
+        H3Index *cells0 = calloc(numRes0, sizeof(H3Index));
+        H3Index *cells1 = calloc(numRes1, sizeof(H3Index));
+        H3Index *out = calloc(numRes1, sizeof(H3Index));
+
+        H3_EXPORT(getRes0Cells)(cells0);
+        t_assert(cells0[0] == 0x8001fffffffffff,
+                 "got expected first res0 cell");
+
+        t_assertSuccess(
+            H3_EXPORT(uncompactCells)(cells0, numRes0, cells1, numRes1, 1));
 
+        // Test various (but not all possible combinations) ranges of res 1
+        // cells
         for (int64_t offset = 0; offset < numRes1; offset++) {
-            for (numUncompacted = numRes1 - offset; numUncompacted >= 0;
+            for (int64_t numUncompacted = numRes1 - offset; numUncompacted >= 0;
                  numUncompacted--) {
                 memset(out, 0, sizeof(H3Index) * numRes1);
 

From 25eecc5d86b78ac14c226047b3e9e9434d93d721 Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Tue, 1 Oct 2024 07:56:45 -0600
Subject: [PATCH 20/20] CHANGELOG

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d29dd51d9..d60ee4241 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@ The public API of this library consists of the functions declared in file
 [h3api.h.in](./src/h3lib/include/h3api.h.in).
 
 ## [Unreleased]
+### Fixed
+- Fixed compacting all or many resolution 1 cells (#919)
+
 ### Changed
 - Replace internal algorithm for `polygonToCells` with a new version that is more memory-efficient (#785)
 - Reorganize tests into public / internal. (#762)